The Houston Dynamo beat D.C. United, 1-0, to move into the semifinals, and D.C. United finished second in Group B thanks to Club America's 3-2 win over Morelia in the final group match played Wednesday night at Toyota Park in Bridgeview, Ill.
Brian Ching scored the only goal in the 50th minute for Houston, which sets up a rematch of their thrilling CONCACAF Champions Cup series with Pachuca on Aug. 14 at Robertson Stadium.
Playing with 10 men after Mauricio Romero was sent off in the 57th minute, Morelia fought back from a 2-0 deficit to tie the score, 2-2, before Federico Insua won the game for America.
The Los Angeles Galaxy and D.C. United meet in the other semifinal on Aug. 15 at the Home Depot Center, assuring MLS of having at least one team in the final on Aug. 29 at a site to be determined.
The Galaxy and Pachuca finished 1-2 in Group A ahead of Guadalajara and FC Dallas.
The 2007 SuperLiga winner will receive $1 million.
Aug. 1 in Houston
Houston 1 D.C. United 0. Goal: Ching (Jaqua) 50.
Houston -- Wells, Waibel, Cochrane, Robinson, Barrett, Ashe (Clark, 68), De Rosario, Mulrooney, Holden, Ching, Jaqua (Ngwenya, 76).
D.C. United -- Perkins, Boswell, Burch (Moreno, 63), Gros, McTavish, Olsen, Carroll (Simms, 83), Dyachenko (Kpene, 35), Gomez, Fred (Namoff, 79), Emilio.
Yellow Cards: Houston - Mulrooney 92+; D.C. United - Burch 61, Kpene 86.
Referee: Baldomero Toledo.