Eddie Johnson and Zach Scott scored to give host Seattle a 2-0 lead, but Robbie Keane was awarded and converted a penalty kick in the 68th minute Sunday that clinched the Los Angeles Galaxy's 4-2 aggregate win and a spot in the MLS Cup final for the second straight year.
The Sounders tried to come back from a 3-0 deficit after getting routed in the first leg of the Western Conference finals last week. Johnson's early goal and Scott's header in the 58th minute pulled Seattle within one on aggregate.
But referee Mark Geiger, who had been the subject of complaints from both sides, called Seattle defender Adam Johansson for a handball in the penalty box, and Keane converted his fifth goal of the playoffs before 44,575 fans.
The Galaxy was without midfielder Landon Donovan (hamstring).
Los Angeles will host the final Dec. 1 against Houston, a rematch of last year's final won by the Galaxy.
The Dynamo tied host D.C. United 1-1 for a 4-2 aggregate win in the Eastern Conference final. Boniek Garcia scored in the 33rd minute for Houston, and Branko Boskovic got a goal in the 83rd for D.C.
Houston, which won MLS Cup titles in 2006 and 2007, might be without midfielder Ricardo Clark for the final as he reinjured a groin.
Tommy Gainey birdied No. 18 for a 3-under 69 and a one-shot win in the Pebble Beach Invitational. Gainey, who won $60,00, finished at 11-under 277. Kirk Triplett
The Czech Republic won the Davis Cup for the first time as an independent nation, beating defending champion Spain 3-2 after Radek Stepanek upset Nicolas Almagro in the last reverse singles. Stepanek won 6-4, 7-6 (0), 3-6, 6-3, converting his second match point before 14,500 fans at O2 Arena in Prague. The Czechs' only previous victory came in 1980 as Czechoslovakia, which split in 1993, with a team led by Ivan Lendl. David Ferrer kept alive Spain's hopes of winning a fourth title in five years by beating Tomas Berdych 6-2, 6-3, 7-5 in the first reverse singles.