David Beckham and the Los Angeles Galaxy will put any celebrations on hold until the Major League Soccer title is secured.

The Galaxy edged past groundshare rivals Chivas USA last night at the Home Depot Centre to secure a place in this Friday night's Western Conference finals against Houston Dynamo.

Chicago Fire and Real Salt Lake meet the following day to determine the Eastern Conference champions, with both match winners advancing to the MLS Cup final in Seattle on November 22.

With a shot at the MLS league title still 90 minutes away, Beckham said the Galaxy would be staying calm in the wake of its 1-0 second-leg victory over Chivas.

"We're not going to get too excited. We're happy we're through and we deserve to be through but it's another step forward to what we want to do," Beckham told ESPN.

"It's what we want to do for this franchise, Tim Leiweke, everybody that's supported us all the way through, they deserve this, the fans deserve this and the players definitely deserve it."

Beckham left the game soon after Landon Donovan had scored the winning penalty in the 73rd minute, looking in some discomfort after taking a knock to his back.

The 34-year-old midfielder, who will miss England's friendly against Brazil in Qatar as a result of the Galaxy's play-off progress, received treatment on the bench as his team-mates held on for victory and said the lower back problem was not a serious issue.

"It's very sore but the win helps. It was a big game for us tonight and a strong performance. We defended really well, especially after the last game. Our defenders were excellent and credit to Chivas but we're happy."