Lewis Hamilton cemented his status as favourite for pole position for the Hungarian Grand Prix by topping Saturday morning free practice.
The Mercedes driver had a quiet start to the session, not going for laptimes on his early laps on the slower medium-compound Pirellis.
Hamilton was down in 18th place when he went out for his third run, still on the mediums, jumping to eighth fastest on his 14th lap on the rubber and then knocking Fernando Alonso's Ferrari off top spot by almost three-tenths of a second on his 16th lap.
But with a big step in performance between the medium and the soft-compound Pirellis, the fastest laps were always going to be set on that rubber.
Hamilton had slipped to seventh by the time he started his qualifying simulation, but he set the fastest times in the first two sectors of the lap and then a personal best in the final one to knock team-mate Nico Rosberg off top spot with four minutes remaining.
Rosberg subsequently improved on his second attempt after a cool-down lap, closing the deficit to Hamilton from 0.453s to 0.229s. He then improved again, cutting the deficit to just 47-thousandths.
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Sebastian Vettel then went third fastest on his qualifying simulation, four-tenths off the pace, with Valtteri Bottas just shaded to fourth fastest by the second Red Bull of Daniel Ricciardo.
Fernando Alonso and Kimi Raikkonen, who had been the first of the frontrunners to go out on the soft Pirellis with 10 minutes remaining were briefly first and second after lapping just 49-thousandths apart.
But they eventually slid to sixth and seventh in the final reckoning, just ahead of Kevin Magnussen's McLaren.
Scuderia Toro Rosso proved it would be a threat for Q3 this afternoon, with Jean-Eric Vergne and Daniil Kvyat ninth and 10th ahead of Felipe Massa and Jenson Button.
Force India drivers Nico Hulkenberg and Sergio Perez were down in 17th and 18th place behind the Saubers and the two Lotus entries, both unable to extract a competitive laptime from the soft rubber.
Kamui Kobayashi continued Caterham's improved weekend by outpacing the Marussias of Max Chilton and Jules Bianchi, with team-mate Marcus Ericsson 21st after a brief spin at Turn 13.
Pos Driver Team Time Gap Laps
1. Lewis Hamilton Mercedes 1m24.048s 21
2. Nico Rosberg Mercedes 1m24.095s +0.047s 24
3. Sebastian Vettel Red Bull-Renault 1m24.455s +0.407s 16
4. Daniel Ricciardo Red Bull-Renault 1m24.678s +0.630s 15
5. Valtteri Bottas Williams-Mercedes 1m24.685s +0.637s 21
6. Fernando Alonso Ferrari 1m24.769s +0.721s 11
7. Kimi Raikkonen Ferrari 1m24.818s +0.770s 19
8. Kevin Magnussen McLaren-Mercedes 1m24.867s +0.819s 21
9. Jean-Eric Vergne Toro Rosso-Renault 1m25.162s +1.114s 17
10. Daniil Kvyat Toro Rosso-Renault 1m25.170s +1.122s 19
11. Felipe Massa Williams-Mercedes 1m25.231s +1.183s 18
12. Jenson Button McLaren-Mercedes 1m25.468s +1.420s 14
13. Pastor Maldonado Lotus-Renault 1m25.829s +1.781s 22
14. Romain Grosjean Lotus-Renault 1m25.859s +1.811s 19
15. Adrian Sutil Sauber-Ferrari 1m25.934s +1.886s 21
16. Esteban Gutierrez Sauber-Ferrari 1m26.023s +1.975s 23
17. Nico Hulkenberg Force India-Mercedes 1m26.035s +1.987s 19
18. Sergio Perez Force India-Mercedes 1m26.142s +2.094s 17
19. Kamui Kobayashi Caterham-Renault 1m27.560s +3.512s 23
20. Max Chilton Marussia-Ferrari 1m28.083s +4.035s 17
21. Marcus Ericsson Caterham-Renault 1m28.605s +4.557s 22
22. Jules Bianchi Marussia-Ferrari 1m28.821s +4.773s 14