The Portland Timbers moved into second in the Western Conference with last-gasp win over the two-time defending MLS Cup champions.
It was the Galaxy who opened the scoring in the 17th minute. Hector Jimenez whipped in a quality cross into the box which Marcelo Sarvas expertly headed home past Timbers goalkeeper Donovan Ricketts.
Ten minutes later the Timbers responded off a quickly taken set piece which caught the Galaxy back line off guard and that Ryan Johnson would eventually capitalize on with a close ranged strike.
The game remained 1-1 for the better part of an hour and it seemed destined to end that way until a late corner was given to the Timbers in the 94th minute. Diego Valeri swung the ball into the box for Jean-Baptiste to jump onto it and the 21-year-old's towering header smashed past LA goalkeeper Carlo Cudicini.
The Galaxy have now conceded 15 goals over the final 15 minutes of games this season.