The Vancouver Whitecaps grabbed a late win and a first home shutout since June to end Houston's five-game run without a loss.
Early in the second half the Dynamo looked as if they had earned a penalty after Carlos Costly was apparently fouled by Joe Cannon in the box. Referee Niko Bratsis initially pointed to the spot, but after a short chat with his assistant changed the decision and awarded a free kick to Vancouver.
It was arguably the biggest moment in the match right up until the last, but Salinas made that decision even more costly in the 86th after being set through on goal by Long Tan. The winger finished expertly, slotting his shot into the corner and giving Vancouver a rare win.
For Houston the loss ends a five game unbeaten run and could prove costly as the club continues to push for the playoffs.