McLaren Formula One driver Lewis Hamilton of Britain walks in the pit building as he heads for the paddock after retiring from the Singapore F1 Grand Prix at the Marina Bay street circuit in Singapore September 23, 2012. Hamilton, who had won two of the last three races, started on pole and was ahead of Red Bull's Sebastian Vettel in second when a gearbox issue left his McLaren stuck in neutral at the start of lap 23.MICHAEL CARONNA/Reuters
McLaren's Lewis Hamilton admitted he needed to win all six races left this season Sunday after a "heartbreaking" retirement while leading the Singapore Grand Prix put a huge dent in his world title hopes.
The 2008 world champion was already scenting his third victory in four races after a third of the race on the skyscraper-dotted street circuit, before a gearbox failure put him out of the running.
"It's heartbreaking not to have finished the race today," said the McLaren driver, who started the night race from pole after a stunning lap in qualifying.
"We definitely had the pace to win this weekend. In fact, before I retired, I was cruising -- just managing the gap back to Seb (Sebastian Vettel, who was then second).
"Then I started to experience difficulty with the gearshift, then I lost third gear, and then the 'box kept dropping into neutral."
Hamilton's retirement brought gasps of disappointment from the crowd. He went into the weekend second in the standings but now lies fourth, 52 points off the pace set by Ferrari's Fernando Alonso, who finished third.
Vettel won the race, claiming only his second victory of the season, while Hamilton's team-mate Jenson Button was second.
"Obviously, I was disappointed, but the good thing we can take away from this weekend is that we have extremely good pace. As a result, I think we can really attack in the next few races," Hamilton said.
"It's going to be hard to close the gap to guys like Fernando and Sebastian (Vettel), especially when they keep finishing race after race, but I'll never give up.
"There are six more races, and I need to go and win all six. I'll fight until the end."
It was a deflating end to a difficult weekend for Hamilton, who has fended off constant questions about his future after he revealed he was considering leaving McLaren, his long-term employer.
Button, who is 75 points adrift of Alonso, rated his own title hopes as "slim". He said his McLaren team needed a drastic improvement in reliability after he also suffered a mechanical retirement at the last race in Italy.
"It's disappointing for the team to have another DNF (did not finish) two weekends on the trot and it's something we need to sort out," Button said.
"As a team over the race weekend we're doing a great job. The pace is there with the car, the last few races, the results have been very good but we just can't seem to do that with both cars.
"It's something I'm sure we need to work on for the rest of the season."