Sebastian Vettel remained unbeatable in qualifying for the Chinese Grand Prix, maintaining the form that saw him top all three Shanghai practice sessions to sweep to his third pole from three races in 2011.
But while one Red Bull sat on top of the qualifying results with a lap 0.7 seconds quicker than the McLarens, the other will start the race in 18th after a disaster for Mark Webber.
His car was repaired from its morning problems in time to join the session, but appeared to be running without KERS and was kept on the harder tyres at the end of Q1 as everyone else near the cut-off went for softs. As Michael Schumacher and Pastor Maldonado made late jumps up the order, Webber found himself 18th and eliminated.
Jenson Button emerged as Vettel's closest rival, but even the Briton was 0.7s adrift of pole as he beat his McLaren team-mate Lewis Hamilton to the outside front row position by 0.042s.
Nico Rosberg gave Mercedes its best result of the year so far with fourth place, only 0.2s down on the McLarens. He comfortable beat the Ferraris, which share row three, with Fernando Alonso ahead of Felipe Massa.
The upper midfield pack was shuffled by a late red flag in Q2, caused by Vitaly Petrov's Renault grinding to a halt on track at Turn 6.
That happened with two minutes left on the Q2 clock, at which point both Toro Rossos and both Force Indias were inside the top 10, while the Saubers, Williams, Mercedes and Petrov's team-mate Nick Heidfeld were not.
In the scramble that followed after the green, both STR drivers and Paul di Resta (Force India) hung on to their Q3 places, while Rosberg was the only man to move from outside the cut-off into the top 10, at the expense of Force India's Adrian Sutil.
Toro Rosso's Jaime Alguersuari and Sebastien Buemi went on to claim the fourth row positions ahead of di Resta. Forced to sit out Q3, Petrov was left 10th.
A mistake at the hairpin left Michael Schumacher's Mercedes 14th behind Sutil and the Saubers. Heidfeld could not do better than 16th, placing him between the two Williams.
Webber's exit was the only surprise of Q1, which also saw the departure of the Lotus, Virgin and Hispania cars. Jerome D'Ambrosio outqualified Virgin team-mate Timo Glock for the first time, and both Hispanias were comfortably within the 107 per cent margin.
Pos Driver Team Time Gap
1. Sebastian Vettel Red Bull-Renault 1m33.706s
2. Jenson Button McLaren-Mercedes 1m34.421s + 0.715
3. Lewis Hamilton McLaren-Mercedes 1m34.463s + 0.757
4. Nico Rosberg Mercedes 1m34.670s + 0.964
5. Fernando Alonso Ferrari 1m35.119s + 1.413
6. Felipe Massa Ferrari 1m35.145s + 1.439
7. Jaime Alguersuari Toro Rosso-Ferrari 1m36.158s + 2.452
8. Paul di Resta Force India-Mercedes 1m36.190s + 2.484
9. Sebastien Buemi Toro Rosso-Ferrari 1m36.203s + 2.497
10. Vitaly Petrov Renault No time
Q3 cut-off time: 1m35.858s Gap **
11. Adrian Sutil Force India-Mercedes 1m35.874s + 1.388
12. Sergio Perez Sauber-Ferrari 1m36.053s + 1.567
13. Kamui Kobayashi Sauber-Ferrari 1m36.236s + 1.750
14. Michael Schumacher Mercedes 1m36.457s + 1.971
15. Rubens Barrichello Williams-Cosworth 1m36.465s + 1.979
16. Nick Heidfeld Renault 1m36.611s + 2.125
17. Pastor Maldonado Williams-Cosworth 1m36.956s + 2.470
Q3 cut-off time: 1m36.147s Gap *
18. Mark Webber Red Bull-Renault 1m36.468s + 1.196
19. Heikki Kovalainen Lotus-Renault 1m37.894s + 2.622
20. Jarno Trulli Lotus-Renault 1m38.318s + 3.046
21. Jerome D'Ambrosio Virgin-Cosworth 1m39.119s + 3.847
22. Timo Glock Virgin-Cosworth 1m39.708s + 4.436
23. Tonio Liuzzi HRT-Cosworth 1m40.212s + 4.940
24. Narain Karthikeyan HRT-Cosworth 1m40.445s + 5.173
107% time: 1m41.941s
* Gap to quickest in Q1
** Gap to quickest in Q2