Emmanuel Boateng set up the only goal for LA Galaxy as they defeated Adam Kwarasey's Portland Timbers to reach the U.S. Open Cup round of 16.

The Ghanaian midfielder's assist helped Raul Mendiola to score in the fifth minute on Wednesday night and the Galaxy made it stand up for a 1-0 victory over the Portland Timbers.

Mendiola took Emmanuel Boateng's centering pass and beat Portland goalkeeper Wade Hamilton.

The Galaxy advance to face the Seattle Sounders in the Cup quarterfinals. The Sounders advanced by defeating Real Salt Lake.

Other matchups in the quarterfinals: New England Revolution vs. the Philadelphia Union; Chicago Fire vs. Fort Lauderdale Strikers; and Houston Dynamo vs. FC Dallas.

All are from Major League Soccer, except for Fort Lauderdale, which is in the second-tier North American Soccer League.