By Steve Keating

MONTREAL (Reuters) - Jenson Button celebrated his greatest victory on Sunday after overtaking Red Bull's Formula One world champion Sebastian Vettel on the last lap of a rain-delayed Canadian Grand Prix thriller.

Button, who earlier had squeezed team mate and fellow Briton Lewis Hamilton into the wall and out of the race, salvaged the weekend for his team by battling back to deny Vettel a sixth victory in seven races.

Despite his error, Vettel stretched his overall lead to 60 points with the 23-year-old German on 161 to Button's 101.

"It's definitely my best race...I'll remember this for a long time," said Button, the 2009 world champion who had never before won in North America and who had to come through from the back of the field.

Button made an amazing six visits to the pitlane -- five regular stops and one drive-through penalty -- before storming back into contention as the track dried and the safety car bunched the field.

"We did a lot of things to contribute to the show today but at the end of the day that was just fantastic," said McLaren team principal Martin Whitmarsh.

"We knew we had to put pressure on Sebastian and he made a mistake. You can forgive him for that. He's driven so well this year but Jenson was just incredible. That's the stuff of champions, that's the stuff of dreams."

"He had the confidence, he went for it, he just attacked and attacked. What a fantastic result for him and the team."


Seven times world champion Michael Schumacher, a seven times winner in Canada, narrowly missed out on the first podium of his comeback by bringing his Mercedes home in fourth place in a race full of incident, several of them involving Button.

The Briton not only had a run with his team mate but also collided with Ferrari double world champion Fernando Alonso -- an incident that could yet cost him dear with stewards reviewing it after the race.

The stewards, one of them former champion Emerson Fittipaldi, also had their hands full with a list of other incidents under scrutiny.

"I've to go see the stewards but at the moment I'm really enjoying this moment because I thought I did the best job I could," said Button.

The 31-year-old Briton could be proud of one of Formula One's greatest charges to secure his 10th career victory.

The race was one of two parts, first water-logged with drivers urging for it to be halted on safety grounds and then exploding into action after the halt as the rain lifted and a dry line emerged.

Vettel, starting on pole for the sixth time this season, was leading when the race was red-flagged and cars ordered to park on the starting grid after just 24 of the scheduled 70 laps had been completed.

After a nearly two hour delay, he was back in front again but under pressure after Button made the right tyre call at the right time and began to take huge chunks of time out of the German's lead.

The race was the first run in wet weather this season and the heavy spray and standing water made for a tough afternoon as cars skidded and spun out around the circuit.

Hamilton's bid for a Canadian Grand Prix hat-trick, after winning on two of his previous three visits, ended after just eight laps when he tried to get past Button along the pit straight and they collided.

"What's he doing?" Button asked in amazement over the team radio while Hamilton parked his damaged car on the track, bringing out the safety car.

Stewards, who have seen Hamilton repeatedly already this season, said they would also investigate that collision after the race.

(Writing by Steve Keating, editing by Alan Baldwin)