The 2010 Seattle Sounders FC season was the club's second season in Major League Soccer, the top tier of professional soccer in the United States. It was the 30th season played by a team bearing the Sounders name. The Sounders opened the regular season with a 2–0 victory over expansion side Philadelphia Union on March 25, 2010, at Qwest Field in Seattle. They closed out the regular season on October 23, 2010, with a 1–2 loss to the Houston Dynamo. Seattle qualified for the playoffs but lost to the Los Angeles Galaxy in the Western Conference Semifinals.