Red Bull took charge in the second Friday practice session for the Korean Grand Prix, as Sebastian Vettel edged out teammate Mark Webber by just 0.032sec.
Vettel arrived in Korea fresh from back to back victories in Singapore and Japan, and having clawed to within four points of Fernando Alonso in the Formula 1 championship fight. Although the Red Bulls were relatively quiet in first practice, they scrapped over the top spot for almost the entirety of practice two.
Michael Schumacher and Felipe Massa briefly intruded early on, but after Webber went fastest on a 1m39.404s just before the half-hour mark, Red Bull was never headed. Its drivers kept exchanging positions, though.
Vettel beat Webber's benchmark by 0.3sec after 34 minutes, and stayed in front until they both moved onto super softs with nearly an hour gone. Webber initially had the edge, taking first place back with a 1m38.864s.
Vettel had made mistakes and locked up on his first super-soft laps, but he then pulled everything together and set a 1m38.832s to secure Friday honors. Alonso ended up Red Bull's closest challenger in third, ahead of Jenson Button's McLaren and Schumacher's Mercedes.
Lewis Hamilton was only eighth in the second McLaren, suffering a major lock-up into Turn 1 on one of his final outings.
In a generally quiet session, other incidents included Sergio Perez's day ending early with an actuator glitch on his Sauber, and Bruno Senna spinning his Williams.
Pos Driver Car Time Gap Laps
1. Sebastian Vettel Red Bull-Renault 1m38.832s 33
2. Mark Webber Red Bull-Renault 1m38.864s + 0.032s 33
3. Fernando Alonso Ferrari 1m39.160s + 0.328s 28
4. Jenson Button McLaren-Mercedes 1m39.219s + 0.387s 29
5. Michael Schumacher Mercedes 1m39.330s + 0.498s 31
6. Felipe Massa Ferrari 1m39.422s + 0.590s 30
7. Nico Rosberg Mercedes 1m39.584s + 0.752s 36
8. Lewis Hamilton McLaren-Mercedes 1m39.717s + 0.885s 25
9. Nico Hulkenberg Force India-Mercedes 1m39.739s + 0.907s 33
10. Kimi Raikkonen Lotus-Renault 1m39.839s + 1.007s 26
11. Romain Grosjean Lotus-Renault 1m39.957s + 1.125s 28
12. Bruno Senna Williams-Renault 1m40.089s + 1.257s 32
13. Paul di Resta Force India-Mercedes 1m40.112s + 1.280s 34
14. Kamui Kobayashi Sauber-Ferrari 1m40.445s + 1.613s 28
15. Sergio Perez Sauber-Ferrari 1m40.745s + 1.913s 11
16. Jean-Eric Vergne Toro Rosso-Ferrari 1m40.789s + 1.957s 31
17. Daniel Ricciardo Toro Rosso-Ferrari 1m40.997s + 2.165s 32
18. Pastor Maldonado Williams-Renault 1m41.200s + 2.368s 33
19. Heikki Kovalainen Caterham-Renault 1m41.602s + 2.770s 23
20. Timo Glock Marussia-Cosworth 1m42.596s + 3.764s 28
21. Vitaly Petrov Caterham-Renault 1m43.067s + 4.235s 21
23. Charles Pic Marussia-Cosworth 1m43.636s + 4.804s 22
22. Narain Karthikeyan HRT-Cosworth 1m43.869s + 5.037s 36
24. Pedro de la Rosa HRT-Cosworth 1m44.533s + 5.701s 24
All timing unofficial