The Los Angeles Galaxy will face the Houston Dynamo in the MLS Cup final for a second consecutive year after the two teams successfully navigated the second legs of their respective conference finals.
The defending champions Galaxy lost 2-1 on the night to the Seattle Sounders, but their 3-0 advantage from the first leg saw them through.
Seattle made a fight of it on home turf though, with Eddie Johnson putting them ahead after 12 minutes and Zach Scott making it 2-0, 2-3 on aggregate, just before the hour mark.
But things began to go sour for Seattle when Adam Johansson handled in the area and a penalty was awarded.
Robbie Keane fired it home and the match ended with Seattle's Osvaldo Alonso receiving a second yellow card after the final whistle, one of several Sounders players to surround the officials to voice their frustrations.
Houston's second leg away to DC United was more straightforward as it ended in a 1-1 draw, Houston's 3-1 advantage from the first leg seeing them through.
Houston were never really made to worry, scoring through Oscar Garcia in the 34th minute, with United unable to reply until Branko Boskovic's strike seven minutes from time.