Handwalla Bwana scored the winner early in the second half as the Seattle Sounders edged Toronto FC 2-1 on Wednesday night at BMO Field.
Will Bruin scored the other goal for Seattle (2-4-2) while Stefan Frei made five saves in the win.
Jonathan Osorio scored the lone goal for Toronto (2-5-1). Alex Bono stopped one shot.
The game was a rematch of the previous two MLS Cup finals. Seattle won the championship in a shootout in 2016 while the Reds blanked the Sounders 2-0 last December.
Tosaint Ricketts had an excellent chance to tie the game 2-2 in stoppage time off a Jordan Hamilton header, but Frei was able to re-direct the shot wide.
Bwana scored his first career MLS goal, taking a through ball from Bruin and beating Bono between is legs in the 54th minute.