HOUSTON — Brian Ching scored six minutes into overtime and the Houston Dynamo advanced to the Western Conference final for the third time in four years with a 1-0 win over the Seattle Sounders on Sunday.

The teams dueled to a scoreless tie in the first leg of their two-game semifinal on Oct. 29, setting up the winner-take-all match in Houston. Fittingly, the league's top two defensive teams during the regular season played 90 more minutes without a goal before Ching's game winner.

The Dynamo advances to the single-game West final to face the winner of the Chivas USA-Los Angeles match later Sunday. Houston improved to 5-1 at home in the playoffs and 9-1-6 at home this season.

The Sounders, an expansion team, wrapped up their inaugural season by losing to Houston for the first time in five games (2-1-2).

Houston defender Mike Chabala set up the winning shot with a high cross from the left. The ball deflected off midfielder Brian Mullan and right to Ching, who beat goalkeeper Kasey Keller with a shot to the top left corner.

Seattle's Freddie Ljungberg shot at Houston's goal about four minutes later, but goalkeeper Pat Onstad leaped to punch it over the crossbar. The Sounders didn't get a better chance the rest of the game.

Seattle defender James Riley earned a red card in the final minute of overtime after tripping Ricardo Clark. The teams exchanged words at midfield before referee Jorge Gonzalez got in the middle of the crowd.

Houston outshot Seattle 15-10.

Dominic Oduro had three of Houston's nine first-half shots, including a drive off the left post in the 23rd minute. The 24-year-old forward from Ghana caught up to a long pass from Stuart Holden in the 30th minute, but his shot crossed just in front of the goal.

Seattle's best chances in the first half came on counterattacks, before the Dynamo's defense could get set.

Fredy Montero ran past a Houston defender, but his close range shot went into the side of the net. Steve Zakuani sent a cross into the goal area in the 36th minute and Houston's Geoff Cameron nearly deflected it into the net for an own goal.

Onstad made a diving stop on Montero's shot in the 57th minute, one of the few scoring chances for either team in the second half.

The Dynamo were back in the same position as they were last season, hosting a decisive game in the West semifinals. They tied New York 1-1 in the first game last year, then lost 3-0 in Houston.