McLaren scored a third successive practice 1-2 as its stronghold over the Hungarian Grand Prix weekend was maintained, but Oscar Piastri was faster than Lando Norris for the first time.
Championship leader Piastri had trailed his team-mate Norris through Friday, but led him here on the initial run on softs - by a quarter of a second.
The McLarens both found huge chunks of laptime when they fitted new softs for the closing minutes, Piastri faster in the first two sectors and Norris clawing back time at the end of the lap - but ultimately coming up 0.032s short.
Ferrari's Lewis Hamilton, who extended his initial stint on the softs, lifted himself up to second between the two McLarens before the mid-session tyre change, but his team-mate Charles Leclerc returned to his familiar third place - which he'd also occupied in FP1 and FP2 - in the end.
Leclerc ended up four tenths back from the best lap of the session, but over three tenths up on Hamilton.
Kimi Antonelli, his confidence seemingly restored by a Mercedes that has shed a difficult suspension upgrade, took fifth, with team-mate George Russell in eighth after a scrappy lap and the two Aston Martins of Fernando Alonso and Lance Stroll behind them,
Sauber impressed like Aston, with Gabriel Bortoleto a superb sixth after the initial runs and ending up ninth despite a modest laptime gain from a new soft, with team-mate Nico Hulkenberg right behind in 10th.
Max Verstappen, who had his worst Friday of the season the day before, remains with some head-scratching to do with his Red Bull team, as he was reasonably competitive after the first runs - fifth-fastest - but struggled badly on new softs at the end.
Reporting that he was inducing understeer, Verstappen found just a handful of hundredths in a lap that looked visibly untidy - ending up 12th - though he at least made better work of it than team-mate Yuki Tsunoda.
Tsunoda's final run was compromised by what his subsequent discussion with the team suggested had been an incorrect setting, so he ended up 19th - ahead only of Isack Hadjar, whose own late push came to an end when he spun on the exit kerb coming out of Turn 13, ruining that set of softs.
FP3 times
1 Oscar Piastri (McLaren) 1m14.916s
2 Lando Norris (McLaren) +0.032s
3 Charles Leclerc (Ferrari) +0.399s
4 Lewis Hamilton (Ferrari) +0.768s
5 Kimi Antonelli (Mercedes) +0.829s
6 Fernando Alonso (Aston Martin) +0.878s
7 Lance Stroll (Aston Martin) +0.912s
8 George Russell (Mercedes) +0.924s
9 Gabriel Bortoleto (Sauber) +1.062s
10 Nico Hulkenberg (Sauber) +1.109s
11 Ollie Bearman (Haas) +1.211s
12 Max Verstappen (Red Bull) +1.246s
13 Franco Colapinto (Alpine) +1.331s
14 Liam Lawson (Racing Bulls) +1.455s
15 Carlos Sainz (Williams) +1.526s
16 Alex Albon (Williams) +1.614s
17 Esteban Ocon (Haas) +1.615s
18 Pierre Gasly (Alpine) +1.654s
19 Yuki Tsunoda (Red Bull) +1.962s
20 Isack Hadjar (Racing Bulls) +2.040s
