Vettel to start last as Rosberg takes Singapore pole
Nico Rosberg claimed pole for Sunday's Singapore Grand Prix with last year's winner Sebastian Vettel set to start from last place on the grid.
Mercedes' Rosberg, winner of both races since the mid-season break, posted the fastest time in Saturday's qualifying at one minute at 42.584 seconds, with Red Bull's Daniel Ricciardo second, over 0.5secs slower.
Defending champion Lewis Hamilton, who holds a two-point advantage over Rosberg at the top of the drivers' standings, could only manage third after a couple of errors in the first sector of his final flying lap left him more than 0.7secs adrift.
He will start on the second row alongside Ricciardo's team-mate Max Verstappen.
Vettel has won four of the last five races in Singapore but a fifth success looks a distant prospect with the German set to start Sunday's race - on a narrow circuit with overtaking chances at a minimum - at the back of the grid.
The Ferrari driver encountered a problem with his anti-roll bar during Q1, with replays showing him rounding some corners on only three wheels as he set the slowest time of the opening session.
Ferrari opted to leave Vettel out on track rather than bring him in to try and fix the problem, frustrating the four-time world champion.
"I was going round on three wheels, which doesn't really work," he told BBC Sport.
"I wanted to come in, but we stayed out, and then I came in because it was just hopeless, we weren't quick enough. But, with just or three minutes or four minutes, there was no time to fix it."
Q2 was prematurely ended when Romain Grosjean - who has been critical of his Haas in recent weeks - spun into the barriers at turn 10.
The likes of McLaren's Jenson Button and Williams' Felipe Massa were left frustrated as the double yellow flags meant they were unable to complete their flying laps, both men believing they were on course to qualify in the top 10.
1. Nico Rosberg (Mercedes) 1:42.584
2. Daniel Ricciardo (Red Bull) +0.531seconds
3. Lewis Hamilton (Mercedes) +0.704secs
4. Max Verstappen (Red Bull) +0.744secs
5. Kimi Raikkonen (Ferrari) +0.956secs
6. Carlos Sainz (Toro Rosso) +1.613secs
7. Daniil Kvyat (Toro Rosso) +1.885secs
8. Nico Hulkenberg (Force India) +1.895secs
9. Fernando Alonso (McLaren) +1.969secs
10. Sergio Perez (Force India) +1.998secs