The Galaxy roared back from an early deficit with two goals in four minutes to advance in the MLS playoffs.
The reigning MLS Cup champion advance to the Western Conference semifinal to play California rivals the San Jose Earthquakes.
Vancouver had won one game in 10 heading into the postseason. However, for much of the match it looked like Canada's first playoff representative might pull off an upset.
In only the fourth minute Matt Watson exploited Sean Franklin's absence due to injury by turning midfielder-cum-fullback Hector Jimenez and racing down the flank. He centered for Darren Mattocks, who opened up his body to prod the ball in off the post.
From then on it was all Galaxy. Los Angeles finished with 73 percent of the possession in the first half and racked up 13 shots to Vancouver's three in that time.
Two of the better chances fell to Robbie Keane. The Irishman lured a crucial last-moment tackle by Lee Young-Pyo in the box and later brought down a long ball deftly to set up a sharp shot which Brad Knighton blocked.
In first half stoppage time Knighton again came to the rescue. First, Andy O'Brien shouldered Landon Donovan over in the box. Referee Silviu Petrescu called the entire match conservatively, and waved away the penalty appeals. Donovan leapt up and helped create another chance, this time with the Galaxy earning a free kick on the edge of the box. David Beckham delivered his trademark flat set piece, which Knighton had to tip away at full stretch.
With their playoff future in the balance, the Galaxy pushed forward. Marcelo Sarvas replaced Jimenez as a nominal right back and the chances kept flowing.
Right after Vancouver nearly caught LA with break from Watson, the reigning MLS champion equalized. Beckham laid off a short corner to Juninho, who crossed. Mike Magee volleyed impressively into the top corner to equalize.
Two minutes later, Martin Bonjour, having spent only seconds on the field as a substitute, shoved Donovan over in the box. This time, Petrescu thought it worthy of a penalty. Donovan may have complained about a lack of motivation this week, but he found the necessary impetus to coolly dispatch the PK and put the Galaxy ahead.
In the aftermath, the referee ejected Vancouver assistant coach Paul Ritchie. With the upper hand in possession and momentum, the Galaxy quickly followed suit and ejected the Whitecaps from the playoffs.
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