A crash decided the Singapore Grand Prix last year, and a crash decided Singapore Grand Prix qualifying this year.
Championship leader Jenson Button, meanwhile, will start from outside the top ten.
Barrichello had looked quicker than team mate and title rival Button in practice. But after the final practice session the Brazilian driver had to change his gearbox, which had been damaged during the race at Spa, and collected a five-place grid penalty.
As qualifying began Barrichello still seemed to have an advantage over his team mate, lapping 0.7s faster with his first effort, setting a 1’47.939. But it wasn’t just the Brawns in contention for the fastest times. Sebastian Vettel soon relegated them both and then Hamilton repeated his pace from third practice by going quickest.
Most of the drivers did three-lap runs to begin with and by the end of it Hamilton was fastest from Vettel by almost six tenths of a seconds.
But Force India were struggling to replicate their Spa and Monza form on the high-downforce Singapore track. Both Adrian Sutil and Vitantonio Liuzzi found themselves in the bottom five with three minutes to go in Q1. Jarno Trulli, Nick Heidfeld and Jaime Alguersuari accompanied them in the bottom five.
The Italian driver failed to reach Q2, and neither did the Force Indias, Romain Grosjean (who went off early in the session) and Liuzzi.
Drivers eliminated in Q1
16. Adrian Sutil, Force India-Mercedes – 1’48.231
17. Jaime Alguersuari, Toro Rosso-Ferrari – 1’48.340
18. Giancarlo Fisichella, Ferrari – 1’48.350
19. Romain Grosjean, Renault – 1’48.544
20. Vitantonio Liuzzi, Force India-Mercedes – 1’48.792
Nico Rosberg delivered the first surprise of Q2, going quickest by half a second. Vettel took second behind him ahead of Hamilton.
In the dying moments of the session it all seemed to have gone wrong for Barrichello. He ran wide at the Singapore Sling chicane, scraped his chassis along the kerb, and lost two seconds.
Both drivers now had a single lap in which to reach the top ten – and Barrichello had a damaged floor. Button’s final effort was scrappy and he failed to improve, while Barrichello launched himself into the final session with a time good enough for sixth place.
Drivers eliminated in Q2
11. Kazuki Nakajima, Williams-Toyota – 1’47.013
12. Jenson Button, Brawn-Mercedes – 1’47.141
13. Kimi Raikkonen, Ferrari – 1’47.177
14. Sebastien Buemi, Toro Rosso-Ferrari – 1’47.369
15. Jarno Trulli, Toyota – 1’47.413
Hamilton began the final part of qualifying fastest. He set a 1’47.891 putting, him 0.3s faster than Vettel, with Rosberg third.
The pair began their final laps with strong first and second sectors, and we looked set for a classic pole position showdown.
But Barrichello ran wide at turn five, lost the back end of his Brawn, and crashed heavily into the barriers. With only half a minute left on the clocks, this brought qualifying to an abrupt halt.
It all worked out rather conveniently for Barrichello. He had been fifth at the time, and it means he will start in front of Button despite his five-place penalty.
But few people could have been very happy to see another session at Singapore decided by a crash. Fortunately there’s no indication there was anything dubious about this one.
After Barrichello takes his penalty, it will promote the new-specification BMWs to the fourth row of the grid, behind Alonso and Glock.
We’ll find out who holds the upper hand for the race when the fuel weights are announced in a few hours’ time.
Due to a technical problem the live blog ended early – sorry for the inconvenience, I’ll look into what went wrong.
Top ten drivers in Q3
1. Lewis Hamilton, McLaren-Mercedes – 1’47.891
2. Sebastian Vettel, Red Bull-Renault – 1’48.204
3. Nico Rosberg, Williams-Toyota – 1’48.348
4. Mark Webber, Red Bull-Renault – 1’48.722
5. Rubens Barrichello, Brawn-Mercedes – 1’48.828*
6. Fernando Alonso, Renault – 1’49.054
7. Timo Glock, Toyota – 1’49.180
8. Nick Heidfeld, BMW – 1’49.307
9. Robert Kubica, BMW – 1’49.514
10. Heikki Kovalainen, McLaren-Mercedes – 1’49.778
Read more: Singapore Grand Prix grid