The Houston Dynamo made sure that Clint Dempsey's return to Texas was not an easy one, taking a 3-1 win on Saturday.
Barnes was the hero of the first half, scoring twice, but a Shalrie Joseph goal pulled Seattle back into the match before Will Bruin finished the game off with his goal in the 74th.
Barnes scored his first in the 17th, with him and Bruin both scrapping away in Seattle's box before the former was finally able to tuck his shot past Michael Gspurning.
The second came just minutes later, with Barnes firing home a laser from 30 yards and giving Houston a comfortable lead to take into the break.
The Sounders, playing with Dempsey in the starting lineup for the first time but without Eddie Johnson, Brad Evans and Obafemi Martins in the starting group, failed to find much of a rhythm in the early going, but did mange to claw back into the game in the 65th.
Joseph was credited with the goal, but the argument could be made that he didn't know much about it. A foul on the right touchline led to to a curled ball in, and Joseph, as part of the scrum of players looking to get on the end up, managed to bundle it home off his body to cut the lead in half.
Will Bruin made sure of the result in the 74th, finishing off a Houston move that included one header coming back off the bar.
In just his second game with the club, Dempsey's chances were limited to a couple of hits with his left foot, only one of which forced a save out of Houston goalkeeper Tally Hall.
The win consolidates Houston's ownership of the final playoff spot in the East, and the Dynamo are now just three points behind the leaders. Seattle will rue missing an opportunity to move up into the postseason berths, as the Sounders are in sixth in the West, one point behind rival Portland.