BUDAPEST, Hungary -- Jenson Button celebrated his 200th Formula One race with a victory at the Hungarian Grand Prix, while Red Bull's Sebastian Vettel stretched his commanding lead in the championship with a second-place finish in wet conditions Sunday.
McLaren's Button was steadiest in the constant drizzle at the Hungaroring circuit to secure his 11th career victory, finishing 3.5 seconds in front of Vettel.
Mark Webber was fifth to stay closest in the standings to his Red Bull teammate, who now leads by 85 points.
Button's first F1 victory also came in Budapest in 2006 in similar conditions, just as his previous win this season came in wet weather in Montreal.
"The reason why we won today is because we are quick. Even if it hadn't rained it wouldn't have mattered," said Button, who won the Canadian GP in June. "It was a very tough race. It was hard keeping it on the road."
Pole-sitter Vettel bounced back from a season-worst fourth place at the German GP, after he was overtaken early by Hamilton and then Button.
The 24-year-old Vettel leads comfortably overall with 234 points, ahead of Webber's 149. Hamilton in third trails Vettel by 88 points, and Alonso is 89 behind. Button is 100 points back. A race win is worth 25.
"I think second today is an important step, although the win was in reach today, but we couldn't get it," Vettel said. "It's clear in the last couple of races they've made some steps forward. There was a chance and we didn't use it, so we have to look into that."
The constant drizzle at the Hungaroring track made for an unnerving race, as cars slipped off track and spun out throughout. Tire strategy proved key, with Hamilton swapping a number of times then finishing with a penalty after forcing Force India's Paul Di Resta off the track as Hamilton recovered from a spin.
Red Bull's inability to convert poles into race wins continued. Vettel led McLaren out of the slick start until the fifth lap, when Vettel ran wide at the second turn for Hamilton to move inside. Red Bull has started all 11 races on pole, winning six.
Button passed Vettel at the same corner nine laps later, while Webber moved into fourth behind Vettel after passing Alonso, who was struggling with grip.
The race settled into a set running order with McLaren cars leading Red Bull's and Alonso vying to get past Webber.
But rain came again as Hamilton spun out to cede the lead to Button after 48 laps, with the pair swapping positions as cars slid off track and even in the pit lane, where Virgin's Jerome d'Ambrosio spun out to send his pit crew scurrying into the garage for protection.
Button eventually went in front after Hamilton pitted to swap tires. Hamilton soon found himself down in sixth position after the penalty but got past Felipe Massa and then successfully challenged Webber on the straight with five laps left to take fourth.
Massa of Ferrari finished sixth ahead of Di Resta, with Sebastien Buemi of Toro Rosso ending up eighth after a 23rd-place start. Nico Rosberg of Mercedes was ninth and Jaime Alguersuari of Toro Rosso took the last point in 10th.
Michael Schumacher of Mercedes dropped out of the race after 28 laps, soon after Nick Heidfeld quickly exited in his Renault, which was engulfed in flames after being released from the pit lane in a smoldering state. Stewards eventually put the blaze out, although Vettel nearly ran into fire officials coming out of a pit stop.