The former Fulham and Tottenham star came into the game earlier than expected when he replaced the injured Obafemi Martins in the 34th minute but managed to get himself through the remainder of the first half before contributing for the entire second half.
Dempsey felt it was important to get back to doing what he does best - playing - and suggested his first appearance for the Sounders will help him get reacquainted with the league he first played back in 2004.
"There has been a lot of talk, a lot of speculation, a lot of media stuff for me but what I enjoy is being on the field and playing," Dempsey said.
"It's what I dreamed about as a kid, being a professional soccer player, and to be able to do that when you are on the field it is home.
"So it was good to get on the field and get some touches, mix it up with the boys and to get familiar with this league again."
Mauro Rosales scored Seattle's first goal in the 16th minute from close range after being found by Eddie Johnson's back post header before Lamar Neagle's cross from the left was swept into his own goal by Toronto defender Doneil Henry five minutes before the break.
TFC got one back through Jonathan Osorio in the first minute of the second half but it wasn't enough as the Sounders held on for a third straight win.
Dempsey went close to scoring a wonderful goal in the 70th minute when he turned two opponents outside the area but Toronto keeper Joe Bendik came up with a fine save to deny him.