Charles Leclerc continued Ferrari's bounceback from its disastrous weekend in France by ending Hungarian Grand Prix Friday fastest as Mercedes seemingly took a step in the wrong direction.
Team-mate Carlos Sainz was quickest in FP1 but in the second session, it was Leclerc who took the honours with a one minute, 18.445secs.
The Monégasque raised concerns over a potential power unit issue but after a quick check of the engine, Ferrari sent him back on track.
But Mercedes endured a torrid session filled with complaints from both Lewis Hamilton and George Russell over the balance of the W13 around the track often likened to a karting circuit.
Lando Norris finished second for McLaren, 0.0217s down on Leclerc although his lap would not have counted in qualifying after running wide and exceeding track limits at the final corner.
Sainz ended the session third ahead of championship leader Max Verstappen, both drivers within three-tenths of Leclerc.
But the Red Bull driver complained of oscillations at turn four and 11 that were "a joke".
Daniel Ricciardo underlined McLaren's apparent pace by ending the day fifth, ahead of Fernando Alonso who celebrated his 41st birthday with a continuation of his recent form.
Sebastian Vettel made the most of Aston Martin's intriguing new rear wing design to finish the day seventh fastest ahead of the first Mercedes of Russell, who complained of weak grip and front locking throughout the hour of running.
Hamilton had a big swap of oversteer at the high-speed turn four, leading to balance complaints from the other side of the Silver Arrows' garage. The seven-time champion finished 11th.
Russell was nine-tenths down on Leclerc's fastest time with Hamilton a further two-tenths back.
Sergio Perez finished down in ninth in the second Red Bull, with Valtteri Bottas rounding out the top 10.
Alex Albon was the only driver to suffer a major drama in the session, with a peculiar rear-locking into turn one sending the Williams driver into a pirouette before continuing.
Hungarian Grand Prix second practice results
1. Charles Leclerc [Ferrari] 1:18.445secs
2. Lando Norris [McLaren] +0.217s
3. Carlos Sainz [Ferrari] +0.231s
4. Max Verstappen [Red Bull] +0.283s
5. Daniel Ricciardo [McLaren] +0.427s
6. Fernando Alonso [Alpine] +0.604s
7. Sebastian Vettel [Aston Martin] +0.808s
8. George Russell [Mercedes] +0.910s
9. Sergio Perez [Red Bull] +0.952s
10. Valtteri Bottas [Alfa Romeo] +0.966s
11. Lewis Hamilton [Mercedes] +1.102s
12. Zhou Guanyu [Alfa Romeo] +1.160s
13. Esteban Ocon [Alpine] +1.169s
14. Lance Stroll [Aston Martin] +1.257s
15. Pierre Gasly [AlphaTauri] +1.285s
16. Kevin Magnussen [Haas] +1.373s
17. Mick Schumacher [Haas] +1.540s
18. Nicholas Latifi [Williams] +2.043s
19. Yuki Tsunoda [AlphaTauri] +2.076s
20. Alex Albon [Williams] +2.170s