Sepang 2015 is the one you know, perhaps the most famous race in the history of not just MotoGP but motorcycle grand prix racing as a whole - but there is no Sepang 2015 without Phillip Island 2015, which makes it one of the most consequential races of all time in the premier class.
Hailed in the immediate aftermath as a classic for the ages, then put under a microscope as Valentino Rossi accused race winner Marc Marquez of race manipulation, the 2015 Australian Grand Prix is everything when it comes to the Rossi-Marquez rivalry.
'The kick' was still to follow, and prior incidents at Termas, Laguna Seca and Assen were cited by Rossi as contributing factors to Marquez's alleged grudge, but ultimately the whole outlook rests on the truth of that one Phillip Island race.
What that truth is - it's not for us to say, and only for a select few to know. But as the Australian GP is the most contentious and the most hazy moment in the rivalry, arguably more so than anything that happened at Sepang, here's what you should know if you don't yet have an opinion here but feel like you'd like to have one.
For an in-depth look at Phillip Island 2015, check out the Australia episode of our MotoGP 2015 Revisited podcast series on The Race Members' Club.
Lorenzo needed every point
The 2015 title race had long been reduced to a two-horse race by then, though come Phillip Island it was only officially so for less than a week.
The previous weekend, Marc Marquez officially ended his title defence with a limp ride to fourth in the wet at Motegi. But it had been a mere formality for a while. Marquez bulldosed his way through 2014 with a title-ensuring 10-win streak, but was saddled with a fundamentally limited 2015 Honda and spent the season crashing it while trying to hang in there with the superior Yamahas.
"Honda brought out a new bike, and it doesn't f***ing work. At one race [Assen], they [the factory team] went back to last year's chassis - and it was back to where they were, and they were competitive," recalled Scott Redding, who also campaigned that year's Honda, in an interview with The Race MotoGP Podcast.
"I spoke to Marquez some years after, he said 'that was the hardest bike I ever had to ride. And I couldn't get results'. He said 'I felt sorry for you that you had to continue with that [2015] chassis'. That's coming from the guy himself."
Points before Phillip Island
1. Rossi - 283
2. Lorenzo - 265
3. Marquez - 197 (out)
4. Iannone - 172 (out)
5. Pedrosa - 154 (out)
While Marquez was long out of the title race, Jorge Lorenzo was teetering. He had the beating of Rossi more often than not in conventional dry races - and, in fact, usually had the beating of everyone - but, after drawing level on points with Rossi just four races at prior at Brno, now stared at an 18-point hole.
This had been set up by defeats in the wet at Silverstone and Motegi, and a costly crash on a drying track at Misano. The 18-point deficit wasn't insurmountable, with 25 on offer for victory and a total of 75 left, but with Rossi almost always on the podium it left Lorenzo with no further room for error, and Rossi on the cusp of premier-class title number eight and grand prix title number 10.
Marquez was heavily favoured pre-race
Ideally Lorenzo needed to win all three remaining races - but Phillip Island didn't look particularly winnable, with Marquez in stellar form.
The year before, he was leading by over four seconds when he crashed out, and in the lead-up to the race this time he led every session but the opening practice.
In the Saturday FP4 session, which under that weekend format came before qualifying and tended to be a pure race pace demonstration, Marquez set nine laps good enough for first place.
Rossi felt on Saturday that Marquez was a clear favourite, though didn't rule out Lorenzo from making it a fight for the win.
Lorenzo, too, said in the press conference that while Marquez had been superior in the cooler morning conditions, his Yamaha crew had made a step forward to "gain a lot of grip" and that gave him some hope of taking on the Honda man.
The race was an outlier
I won't spend too much time on the specific moments of the race itself - we go into a lot of detail in our 2015 Revisited episode, but also simply too much happened - and the question of whether any of it was 'dodgy' can only be hoped to be answered satisfactorily through viewing the actual footage of what was effectively a race-long dogfight between Marquez, Lorenzo, Rossi and Andrea Iannone.
But, in short, is there any ground for doubt here? Was it, at least, an unusual race?
Yes, it was. And was it an unusual race even by Phillip Island standards? Yes, it was. That's clear on the timing alone - and it is why Rossi came into his media scrum at Sepang brandishing a printout of the race times, though more on that later.
Marquez capped the race with the fastest lap, a 1m29.280s, but he was consistently in the 1m30s range just a handful of laps prior. And his pace modulated a lot, even in clean air and not just while being attacked by Rossi and Iannone.
Lap 26/27
1 Lorenzo
2 Iannone, +0.662s
3 Marquez, +0.778s
4 Rossi, +0.927s
Lap 27/27, chequered flag
1 Marquez
2 Lorenzo, +0.249s
3 Iannone, +0.930s
4 Rossi, +1.058s
The year before, he had been reeling off very consistent laptimes - admittedly in clean air and admittedly until he fell. But the footprint of his race times in 2015 was a very distinct one.
In the last 20 dry Australian Grands Prix, this was one of just three with a negative lap number-to-laptime correlation for the race winner. In very simplistic terms, what that means is the pace got quicker, on average, the further into the race you got - which is unusual for Phillip Island in MotoGP.
The other two races? The 2000 500cc season finale, an archetypical Phillip Island melee won by Max Biaggi, and the 2003 race in which Rossi earned a 10-second penalty so had to absolutely gun it to negate it at the finish.
The negative (positive?) pace trend was actually a lot more pronounced in those than in the Marquez 2015 ride, which in that aspect is actually more similar to his own wins from 2017 and 2024 and Maverick Vinales' 2018 triumph.
The more interesting metric is the lap-to-lap laptime variation, which we've measured here by looking at how much - in absolute value, so ignoring if it's a gain or a loss - on average the winner's laptime changed from one lap to another.
Here are the five winning rides with most variability - and five with the least variability - from the last 20 (with the last lap sometimes excluded from the data if the winner obviously rolled off to celebrate).
Most
Valentino Rossi, 2001 - 0.418s per lap
Max Biaggi, 2000 - 0.365s per lap
Marc Marquez, 2015 - 0.363s per lap
Valentino Rossi, 2005 - 0.307s per lap
Marc Marquez, 2017 - 0.292s per lap
Least
Johann Zarco, 2023 - 0.196s per lap
Valentino Rossi, 2014 - 0.206s per lap
Casey Stoner, 2007 - 0.207s per lap
Valentino Rossi, 2004 - 0.208s per lap
Maverick Vinales, 2019 - 0.224s per lap
More exciting races will naturally create more laptime variance - see also, 2017. But if you wanted to take this as evidence that Marquez was at least seriously constraining his pace, given what he was able to unleash on the final lap to overcome a 0.778s deficit to Lorenzo (while clearing Iannone), you could.
How Marquez explained it
Marquez, for his part, didn't necessarily claim that he was trying to stay in the pack, avoid clearing off into the distance like the year before (which ultimately led to his crash), win at the slowest possible pace, anything like that. Instead, there was a purely technical explanation.
"Honestly, some parts of the race I was struggling," he said. "In the warm-up [in the morning] I felt really good, good rhythm, then in the race the temperature came up. In the beginning it was difficult to find especially the front feeling.
"I tried to catch Jorge, I overtook him, I tried to push, but then I saw that the front tyre was moving a lot, with this temperature. And I said 'OK, it's time to cool down again and try to manage until the end'. But it was always closing, I had some moments.
"My plan was to try to push a little bit more in the last three laps. Then Iannone and Valentino overtook me, and it was difficult to manage. Honestly, I didn't believe I would arrive to Jorge."
Why did he "arrive to Jorge"? Why would he, if he was race-manipulating?
"If I wanted to help Lorenzo, I wouldn't pass him in the last lap, I wouldn't push on the limit, I wouldn't take the risk. I don't know why they say [this]," Marquez responded when put on the defensive at Sepang.
"I already said, and also we saw on the data with the team and everything, that the Honda is pushing a lot the front tyre, and in this race it was the softest compound that we have.
"But it was the only tyre we could race, and I was struggling a lot during the race, 27 laps in a row. I tried to manage well the tyre, but it's true that in the middle of the race I tried to push and I tried to open a gap and it was not possible."
Rossi's suspicions arrived late
It is important to note here that, in the immediate aftermath of the race, none of the parties involved felt anything suspicious had taken place.
Yamaha boss Lin Jarvis acknowledged: "For me it was something completely unpredictable, because just when you started to get an idea, 'OK, this is the race pattern, this is how it's going to be' - and then it all changed. And then it all changed again." But Jarvis was raving, not complaining.
Rossi, a fourth-place finisher behind Iannone, himself said that Marquez overtaking Lorenzo on the last lap "is important because it's five points" and thus the race outcome is "OK, like this, but could've been better if I was able to overtake Iannone on the last lap", with Rossi ceding seven points to Lorenzo.
"It was a good race."
Points after Phillip Island
1. Rossi - 296
2. Lorenzo - 285
3. Marquez - 222 (out)
4. Iannone - 188 (out)
5. Pedrosa - 165 (out)
Between that post-race debrief and the Thursday press conference at Sepang, everything changed. The story goes that somebody got into Rossi's ear - and that, rewatching the race, he suddenly saw not a classic Phillip Island tussle, but extreme manipulation, so much so that he decided to publicly offer up the theory at Sepang, in quite some fashion.
Just minutes after deriding those who criticised Iannone for how the Ducati man raced him at Phillip Island as "not my real supporters", Rossi said: "I saw a lot of times the race in Phillip Island, and it was very interesting.
"It was a great battle, no? I don't know how many overtakes, more than 50 maybe. High-speed, good level, great bikes, great riders.
"If we can see another race like this - especially we have to speak with him, with Marquez. Because...during the race it was more difficult to understand, but after when I saw the race later, it was very clear that he played with us very much.
"Mainly I think that his target was not just to win the race, but also to help Lorenzo to go far and try to take more points than me. I think that from Phillip Island it's very clear that Jorge has a new supporter, that is Marc.
"This changes a lot, because for sure Marc had the potential to go away alone - and for sure it could've been another type of race."
All of that was said through smiles and laughter - from Rossi, from Marquez, a smirk from Lorenzo. A subsequent addition from Iannone, pouring fuel onto the fire, was that "I also think Marc played with us" and "I don't know why, for sure he had really good pace, it's a strategy, I don't know, but OK".
Rossi then went a lot further as Italian media huddled around him in the immediate aftermath of the press conference - pulling out the laptime documents, describing what Marquez did as "obvious", questioning whether Marquez really was a fan growing up as he claimed, insisting that Marquez was "competing with me" in terms of total number of world titles - and that this was Marquez's motivation to help Lorenzo instead.
Rossi clearly hoped that throwing all this out in the open would put some public pressure on Marquez that would be advantageous to Rossi in the title fight. Whatever the truth of Phillip Island 2015, in this calculation - as proven at Sepang - he was wrong.
The question that remains
There is no shortage of question marks about that moment in time even 10 years later, and a lot of them are about Sepang - namely, did Marquez deliberately mess with Rossi in that race (it sure looked like it) and did Rossi actively kick him off the bike (it kind of doesn't matter, because either way he sure caused him to crash)?
But Phillip Island is the most important mystery, and while both versions of the events there are compelling, one of them has a potentially insurmountable question at the centre.
If Marquez was playing for Lorenzo - well, uhh...why didn't he let Lorenzo win? Asked at Sepang whether Marquez had helped him at Phillip Island, Lorenzo turned the sarcasm dial up to 11: "Yes. Mainly in the last lap. A lot."
It would've been very easy to accept second place from the position Marquez was in, and Lorenzo sure needed the five points. It would've meant a deficit of six instead of 11 coming out of Phillip Island, and would've meant Lorenzo could guarantee the title with two wins - rather than needing more riders to slot in between himself and Rossi.
Is there a satisfactory answer to that question?
Did Marquez want to have his cake and eat it, too - help Lorenzo but also take a first Phillip Island MotoGP win after a crash in 2014 and a disqualification the year before?
Did he miscalculate and then 'luck out' by just having enough time to overtake Lorenzo on the final lap, despite the huge gap?
Or did he ride perhaps the greatest race anyone's ever ridden, able to manipulate every rider into the finishing position that he wanted them to end up in?
That's for you to decide for yourself. Rossi, as the decade since the 2015 run-in has proven, is certainly not budging.
