The Vancouver Whitecaps earned some revenge and a big three points on the road while also leaving Montreal coach Marco Schallibaum and the Impact hopping mad.
Kenny Miller scored from the penalty spot and Camilo Sanvezza came off the bench to add two late goals as the Whitecaps kept their playoff hopes alive with a 3-0 victory over the sagging Impact on Saturday afternoon.
But it was a penalty that referee Jorge Gonzalez called, then overturned, in the first half that had Schallibaum, Montreal's oft-suspended coach, in a lather.
Vancouver led 1-0 in the 38th minute when Patrice Bernier's shot from distance after a corner kick glanced off Jun Marques Davidson's arm or shoulder at the left post.
With Impact players calling for a penalty and Whitecaps players and coach Martin Rennie screaming no foul, Gozalez hesitated, then pointed to the spot. He then changed his mind after consulting with fourth official Mathieu Bourdeau.
"It's a scandal," said Schallibaum, the first-year coach who has been suspended four times for a total of five games for various infractions. "A decision was made and all of a sudden, it's not made.
"I'm not saying that won the game, but if we have this penalty and it's 1-1, it can change a lot of things."
The Whitecaps (11-10-8), who began the day seventh in the Western Conference, ended a string of three straight road games with a win that keeps them in the crowded Western Conference playoff race
The Whitecaps ended a five-game winless run and picked up only their second victory in 10 games. Montreal (13-9-6) lost a second straight home game.
"We had three road games and we wanted to get four points and we did," said Rennie. "A 3-0 result is good anywhere, but to get it against a rival and a good team like Montreal shows the team is coming together."
It also avenges Montreal's win on the away goals rule in a two-game series in the Amway Canadian Championship in May.
There was no argument about Miller's goal in the 23rd minute.
Vancouver looked to be the fresher team from the start and struck first after Nigel Reo-Coker blew past 37-year-old Alessandro Nesta on the right side. As he crossed the ball, defender Hassoun Camara fell and, as he was getting up, Matt Watson's shot hit his arm in the 23rd minute.
Gonzalez had no choice but to call a penalty. Miller made no mistake with his eighth goal of the year but only his second in the last 10 games.
Bedlam came 15 minutes later on the disputed hand ball.
Whitecaps defender Jay DeMerit said the refs got it right in the end by consulting a video replay.
"It's using the system in a positive way," he said. "Every team had been burned on penalties that weren't penalties.
"And the whole point of having a fourth official and the whole point of taking an extra 30 seconds to make sure that call was right is the reason for this. We use this technology and we use our fourth officials to make sure we make the right calls.
"Thankfully for us, he made the wrong call and corrected himself, because the last thing you want is it to be a tie game when it actually wasn't a hand ball."
That's not how Montreal saw it.
"I've never seen anything like that," said veteran midfielder Justin Mapp. "I had a good view of it.
"I don't think I've ever seen a reversed PK call, but I'm not an official. It's tough to get that call at home. It would have helped us."
The officials released a statement after the game that the decision to reverse the call was made by the entire crew, which found that "there was not an intentional handling of the ball on this play."
It added that: "The referee crew determined that the ball struck the Vancouver player's chest/shoulder area of the body with no intention to play the ball with his hand."
Montreal pressed hard in the second half and nearly tied it as Felipe Martins volleyed Mapp's pass off the bar and another Felipe shot was tipped off the bar by goalie David Ousted.
Then Camilo got one on a counter-attack in the 89th minute and another in added time — his 15th and 16th of the season — to put the game away.
"We were disappointed not to win the Canadian Championship, but fair play to Montreal — they came into our stadium and beat us to win it," said DeMerit. "But the league takes precedence.
"To come back and get a win right now was a huge step for us going into the final games of the season. We needed these three points."
Fatigue may have been a factor for Montreal, which was playing its third game in eight days. It was a week to forget, as the Impact blew a lead and lost 2-1 at home last weekend to Columbus, then was beaten 3-0 in San Jose in CONCACAF Champions League play.
"Obviously, we want to correct those things," said Mapp. "We wish we were winning games by shutouts, but sometimes that's how it goes.
"You've got to move onto the next game. We'll be men and a correct what's wrong. But I thought we were the better team. The 3-0 scoreline is a bit misleading."
Felipe will sit out Montreal's next game after picking up his fifth yellow card for a dive in the Vancouver area.
Miller was substituted in the 60th minute by Camilo and Russell Teibert went in after 65 minutes for Tommy Heinemann.