"The players understand what's on the line," team manager John Hackworth said. "We talk about it enough. It's just disappointing. Tonight was our opportunity, and we let ourselves down.
"This was a playoff game before the playoffs. Both of us had to win tonight, and our expectations were that we were going to come here and get the victory. We did a good job in the first half. We didn't finish off the game."
Fabinho opened the scoring for Philadelphia in the 28th minute, his first goal of the year. The Brazilian defender took a well-placed through ball from Jose Kleberson and fired a powerful leftfooted strike past Impact goalkeeper Troy Perkins.
Up by 1-0, the Union were sitting pretty at halftime. Forward Conor Casey thought the Impact came out with too much energy in the second half.
"They threw a lot of numbers forward and we had a couple of decent chances but didn't play well enough to come away with the three points," Casey said.
"Not being able to pull away, we let them come back, and they did."
Veteran striker Marco Di Vaio tied the game with his league-leading 20th goal in the 64th minute of play when he turned and beat keeper Zac MacMath on his far post from close range.
"I saw the shot," MacMath said. "He just had way too much time, and he really could pick it out wherever he wanted to. And obviously he did."
MacMath couldn't do much on Montreal's second goal, either. The Impact got the winner in the 84th minute when an unmarked Karl Ouimette scored his first-ever MLS goal, a header off a Justin Mapp free kick.
"It was a good ball by Mapp," MacMath said. "I think if I get a good jump on it, it's a ball I can come out for."