SINGAPORE (Reuters) - Lewis Hamilton felt a mixture of elation and exhaustion after converting his stunning pole position into a victory at the Singapore Grand Prix on Sunday as the Briton tightened his grip on a fifth Formula One world championship title.

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Once Hamilton got a clean start at the Marina Bay Street Circuit, he could control the race from the front and although he stretched his advantage over Sebastian Vettel to 40 points with six races remaining, the Briton admitted he was shattered.

“I’m spent! That was a tough race, I have such great support here and we had a great start,” Hamilton said after claiming victory at the 23-turn floodlit circuit for the fourth time in his career.

“The team had never given up faith and belief in me and (team mate) Valtteri (Bottas). That was the longest race in my life and its a blessing. I’m just blessed.

“It was long, but it was still fun. Driving this track is incredible, especially with these cars.”

Mercedes have long regarded Singapore as a “bogey track” and were fearing the worst as Vettel’s Ferrari team and the Red Bulls dominated practice, but Hamilton drove a perfect lap to qualify first and was never really threatened in the race.

“I got a great start and was able to control the pack, control the tires and push where I needed to push,” he said after crossing the line almost nine seconds ahead of Red Bull’s Max Verstappen with Vettel way off the pace in third.

“We knew they (Ferrari) were going to be spectacular here this weekend and we knew it was going to take something quite special to beat them.

“It was quite a monumental moment for us as a team. I definitely didn’t think I’d come to Singapore with 10 points more (in the lead of the title), but I’m very grateful.

“The Ferraris put a good fight this weekend but I’m not sure where their pace went in the race.”

Hamilton did have one minor scare on lap 38 when he got caught up behind some back markers and Verstappen closed right up behind him. He held off a brief challenge from the Dutchman and raced away once he had clear track in front of him.

“I was a little but unlucky with the traffic, these guys (Haas’ Romain Grosjean and Williams’ Sergey Sirotkin) were moving and it was difficult to follow,” Hamilton added.

“Max was lucky I think, and the guys wouldn’t let me by, my heart was in my mouth but once I got past I could put the pedal down and just had to go.”

The next round is in Sochi, Russia on Sept. 30, where Hamilton has won twice before and Mercedes all four races since it was added to the Formula One calendar in 2014.