The Impact looked to be cruising to a win after Marco Di Vaio's Major League Soccer-leading 18th goal in the 23rd minute when the crafty Federico Higuain went to work, setting up a pair of second-half goals in the Crew's 2-1 comeback victory on Saturday afternoon.
Defender Chad Marshall and striker Dominic Oduro scored for Columbus (10-14-5), which has been a thorn in Montreal's side this season.
The Crew, who handed the Impact only their second home loss of the season, won the season series with Montreal 2-0-1, taking five of six points at Saputo Stadium.
Impact coach Marco Schallibaum uses the French term "bete noire" to describe Columbus, which his players know means nemesis.
"It's football — you always have a bete noire," said Schallibaum. "It's very hard to explain."
This one was straightforward. The Impact wasted several chances to make it a 2-0 game, and pushed so hard for a second goal that they left themselves open for talent like Higuain to make them pay.
The first was a smartly curled free kick that found Marshall's head on the left side of the penalty area in the 66th minute to tie the game.
The second came after Justin Mapp lost the ball in the midfield and Higuain sent a perfect pass that the onrushing Oduro got a toe on in the 79th.
"It's difficult to explain, but every time we play against Columbus it's a difficult game for us," said Impact defender Matteo Ferrari. "We started well.
"In the second half, we were in control and also had some chances. It was important to score the second goal and we didn't. They got the second goal with a mistake in the midfield and then it was difficult to come back."
The game-winner was Oduro's 10th of the season, including one in each game against Montreal.
"It looks like I have their number, but at the end of the day, we just played well," said Oduro. "We wanted to get a result and we did. We played well and made it happen."
Montreal (13-8-6), which entered the day in a tie for first place in the Eastern Conference, ended a four-game unbeaten run with a game they should have had salted away by the intermission.
The Impact got the early lead Patrice Bernier lofted a pass over the penalty area to Ferrari, who headed into the middle for Di Vaio to nod in for his seventh goal in the last five games.
But Mapp was stopped from point blank by Matt Lampson in the opening minutes, captain Davy Arnaud just missed converting a Di Vaio pass, Felipe Martins froze on a chance from close range, Di Vaio wasted one when he cut left instead of shooting, and Jeb Brovsky was stopped by a diving save at the end of the half.
Di Vaio had another chance early in the second half, but was stopped.
"I don't think they were hungrier than us, I just think our focus was maybe too much on getting the second goal and we didn't do a good enough job covering space when we were going forward," said midfielder Collen Warner.
It was a game they were counting on to win. Schallibaum started his first 11, not saving any veterans for a key CONCACAF Champions League game in San Jose on Tuesday night.
"It's very disappointing," said Arnaud. "I thought we created a ton of chances.
"We could have put the game out of reach. We talked before the game about how dangerous they are on set pieces and it hurt us because they got back in the game on a set piece."
It all added up to another setback against Columbus, a team that lost eight of 11 games before making a coaching change on Sept. 2. Interim coach Brian Bliss has two wins and a loss since taking over.
Now the Crew hope to put a streak together to try to climb back into the playoff hunt. They are on the tail of Chicago, Houston and England for fifth place and final a post-season berth.
"This was critical to our goal of getting a playoff spot," said Bliss. "Now we've put some pressure on some teams that are ahead of us."
Montreal resumes league play Saturday against the visiting Vancouver Whitecaps.