It was the first time this season that the Sounders (13-6-8, 47 points) won after allowing the game's first goal.
Alex Caskey started the play that led to the game-winner with a short pass to Fredy Montero on the attacking left side. Montero, going stride for stride with Shalrie Joseph of Chivas, got a step in front of him and crossed the ball through the penalty area.
Johnson met it 8 yards in front of the net and headed it hard off the hands of goalkeeper Dan Kennedy and into the back right corner.
''If it would have hit my foot, I probably would have been a little more nervous,'' said Johnson, whose 13th goal broke Montero's single-season team record.
''It was a great ball by Fredy. I was just trying to get enough pace on it and get it down. I didn't expect (Kennedy) to get to it. I was just trying to get it down as hard as I can.''
Of Johnson's 13 goals, 10 have come on headers.
''It adds a dimension to our team. We really haven't had that option in the box for a while,'' Seattle coach Sigi Schmid said. ''I'll take them off headers, off his foot, off his chest, I don't care - as long as they go in.''
Nick LaBrocca opened the scoring for Chivas (7-12-7, 28 points) in the eighth minute. He took a short through ball from Joseph, turned from 16 yards in front, and beat Sounders goalkeeper Michael Gspurning to the back right corner for his second of the year.
Johnson answered in the 28th. With a free kick 10 yards up from the goal line on the far left side of the field, Christian Tiffert floated the ball toward the far post. Johnson, from the top right corner of the 6-yard box, sent a header down to the turf, and it bounced over Kennedy's outstretched arms and into the upper right corner.
With seven games left, Johnson is two goals short of his MLS high of 15, achieved with Kansas City in 2007.
''Fortunately, I'm on with guys who are good out wide and serve some great balls into the box,'' Johnson said. ''That's one of my strengths, and the guys are starting to realize that.''
Chivas USA, routed 6-2 at home by the Sounders on Aug. 25, came in with a defensive focus, and that ultimately led to its early lead.
''We made it very difficult for them to get attacking chances against us, and obviously we created some pace for ourselves and scored an early goal - a good goal,'' coach Robin Fraser said. ''And then slowly but surely, we got less and less confident on the ball, which led to more turnovers, which led to the rest of the game.
''We defended fairly well. (But) on the attacking side, we just weren't good enough.''
Prior to Saturday's comeback, the Sounders had been 0-6-4 when allowing the first goal this season.
''It showed our character being able to do that,'' Schmid said. ''This year, we got off to a good start and scored early goals all the time. Then we hit that (nine-game winless) streak, and came from behind to tie once or twice, but not to win.''
- Eddie Johnson
- Seattle Sounders
- Chivas USA
- Fredy Montero