MONTREAL -- Jenson Button spent 69 laps soaked by the spray spinning off the tires of rest of the field at the Canadian Grand Prix.
Sebastian Vettel's only view was of the flashing lights on the safety car.
Button worked his way up from last place and took advantage of Vettel's last-lap slide to pass the Formula One points leader on the final trip down the backstretch and win the rain-soaked and rain-delayed Canadian Grand Prix on Sunday.
"I think even if I hadn't won today, I would have enjoyed the race immensely," said Button, who finished second here last year. "I enjoyed it very much coming through the field. Fighting your way through the field is almost as much fun as winning the race. It's a great feeling to get on someone."
Button had fallen to 21st after two run-ins with other cars and a speed limit penalty, but he steadily moved up and ran the fastest lap of the day in Lap 69 to sit less than 1 second behind Vettel entering the final trip around the Circuit Gilles Villeneuve. As the German navigated a chicane on the backstretch, the rear of his Red Bull car slipped wide on the slippery track and Button sped past him to take the checkered flag for McLaren.
"We led every single lap except for the last one -- or part of the last one," Vettel said. "It was probably the only mistake I had in the whole race. I went a little bit wide. If it would have been dry, no problem. ... But I ended up in the wet, and it was quite easy for him to pass. It was a difficult day to race, easy to make mistakes, so it is good to get points. But if you've got it in your hands and then you give it away, it's not the sweetest feeling."
It was Button's first victory this season and the 10th of his career. He had to sweat out a steward's investigation over an incident with Fernando Alonso, but no penalty was given.
Mark Webber was third in the other Red Bull car, and six-time world champion Michael Schumacher was fourth. Schumacher narrowly missed out on his first podium finish since coming out of retirement last year, sitting second behind Vettel late in the race before he was overtaken by Button and then Webber.
"I am leaving this race with one eye laughing and one eye crying, as I am not sure if I should be excited or sad about it," Schumacher said. "I would obviously have loved to finish there and be on the podium again. But even if it did not work out in the very end, we can be happy about the result and the big fight we put in."
Vettel had won five of the first six Formula One races this season -- and six of the first seven poles -- and except for a pit stop on the 20th lap he traveled the first 69 laps trailing only the safety car that made seven trips onto the course because of the rain.
The race started under a slight drizzle that grew into a full-fledged downpour by the 25th lap that drenched the track and limited visibility before the red flag came out. After a delay of 2 hours, 4 minutes, the cars were back on the track with mandatory wet weather tires.
It was the first time this year that Formula One drivers have had to drive in the rain, and the first time they have done so since the circuit switched from Bridgestone to Pirelli tires. Many teams went with the full "wet" tires early, but others gambled on an intermediate set that seemed to pay off before the race was red-flagged.
Button, who started in the fourth row, dropped to the back of the pack because of two minor collisions and a penalty for a speed limit violation. But, with the intermediate tires, he quickly moved up to 10th before racing was suspended.
Vettel continued to lead when the race resumed, but Button continued to move up and ran the 69th lap in 1 minute, 16.956 seconds to close within 1 second of Vettel. He won by 2.709 seconds.
"As we always say, the last lap is the important one to be leading," Button said. "And I was leading half of it."
Lewis Hamilton, who had won two of the last three races here -- there was no event in 2009 -- was knocked out after trying to pass Button near the start-finish line in the early part of the race. With the poor visibility, Button did not see him and he squeezed Hamilton into the wall.
Hamilton, who entered the day in second place in the championship standings, trailing Vettel 143-85, received zero points and fell further behind in the points race.
"I felt like I was halfway up to the outside of him and he just kept moving across, whether or not he saw me or not ... and I was in the wall," Hamilton said. "This is racing, and I feel sorry for the team; they've worked so hard this week, we could have really done with the points. (But) it was kind of lucky we didn't take both ourselves out."
With his racing day over, Hamilton spent part of the rain stoppage guiding Grammy winner Rihanna through the McLaren garage, giving her an up-close look at his car.
Alonso followed him to the garage in the 38th lap, tapping tires with Button and spinning backward toward the wall. His car was hung up on the curb and a brief effort was made to push it back onto the track before a track worker waved his arms; Alonso, who is fifth in the championship standings and second on the starting grid, was out of the race.
There was a scary moment when a track worker slipped while picking up the debris from the Heidfeld wreck, then dove out of the way as the oncoming traffic, brakes smoking, managed to swerve to avoid him.