By John O'Brien
SINGAPORE (Reuters) - Sebastian Vettel put pole position on the line with a bold and risky gamble that paid off, after an anxious wait, at the Singapore Grand Prix on Saturday.
Red Bull's triple Formula One world champion was able to celebrate his 41st career pole while watching the monitors in the team garage after deciding not to go out for a final quick lap around the floodlit Marina Bay street circuit.
The championship leader had stormed to the fastest time ever seen in Singapore and retreated to the garage content that his one minute 42.841 second lap would be enough to hold off his rivals.
It turned out closer than he had imagined, with fellow-German Nico Rosberg ending the session just 0.091 seconds slower for Mercedes to line up alongside on the front row of the grid for Sunday's race.
Lotus's Romain Grosjean and Vettel's Red Bull team mate Mark Webber qualified third and fourth.
"I knew we had a cushion which is why we decided not to run again but the thing you don't know is how much the track improves and I'm sure there was a little bit of track ramping up," Vettel told reporters after his fifth pole of the season.
"We thought it was good enough... but probably a bit close."
Vettel now looks set fair to record a hat-trick of victories in Singapore and extend his 53-point lead over nearest rival Fernando Alonso of Ferrari, who could only finish seventh.
"Rocky (race engineer Guillaume Rocquelin) asked me if I was happy not to run again and stay in the garage and I said 'yes I'm happy'. He asked before how much I could improve if I go again and I told him probably there was a tenth maybe two," added Vettel.
"So I thought there was a tenth in me... it was very close and it was not the best feeling when you stand there and watch."
Red Bull team principal Christian Horner said it was a huge relief to see off the late challenge from Mercedes after Vettel appeared so dominant.
"We were happy after the first run but then Rosberg started going very quick," he said. "We asked him (Vettel) if he thought he could go any quicker, he said a tenth. So we thought hopefully that should be enough and in the end it was pretty tight."
Mercedes boss Ross Brawn paid tribute to Red Bull's brave decision to save a set of tires for the race.
"I suspect the track just picked up a little bit at the end but it was a pretty brave move. It was a tenth or less than a tenth between the two of them, that's pretty ballsy," Brawn said.
"I wouldn't have felt comfortable doing that because the track does change. Having said that, he's given himself a fresh set of tires tomorrow for the race so it's worked out for them. But a super, super effort from Nico.
"That's the great thing about the two drivers we have, that they push each other hard. Not quite so great for Lewis (Hamilton) but I think he'll be a in a good position (fifth) for the race tomorrow."
(Editing by Alan Baldwin)