06/01/2013 10:50 EDT | Updated 08/01/2013 05:12 EDT

Nyassi, Warner score early in 2nd half and Montreal Impact rally for 2-1 win over Sporting KC

KANSAS CITY, Kan. - Just three days removed from winning the Amway Canadian Championship, the Montreal Impact pulled out a gutsy comeback win in Kansas City to move into first place in the MLS Eastern Conference.

Sanna Nyassi and Collen Warner scored early in the second half Saturday night, rallying the Impact for a testy 2-1 victory over Sporting KC.

Despite falling behind 1-0 at halftime on a controversial penalty kick and having coach Marco Schallibaum dismissed for the second time this season in a match against Sporting KC, the Impact (8-2-2) claimed the win on tired legs.

"We showed a lot of character," Montreal assistant coach Mauro Biello said. "It was a difficult week for us with the Canadian championship on Wednesday in Vancouver. We had to fly across the country and had players playing three games in a week, so great character that we showed today."

The Impact's first trip to Kansas City on March 30 ended with the season's first loss, a 2-0 defeat in which Montreal was beaten soundly.

By contrast, Montreal outplayed Sporting KC in the rematch, but found itself trailing by a goal after Claudio Bieler converted a penalty kick in the fourth minute of first-half stoppage time.

"Before the PK, we were in control of the game," Nyassi said. "We dominated every area on the field."

And it seemed as if it might be for naught.

Defender Alessandro Nesta tugged Bieler's jersey as the two jostled for position near the top of the penalty box.

As Jimmy Nielsen's goal kick sailed downfield in the waning minutes before halftime, Nesta's arm was resting on Bieler's shoulder when the Sporting Designated Player went down a step into the penalty box.

Referee Armando Villareal conferred with assistant referee Greg Barkey and gave the penalty, which Bieler — an Argentinian-born forward acquired from Ecuador's LDU Quito in the off-season — coolly converted for his seventh goal of the season.

Montreal continued to protest Villareal's call after the whistle to the point that Schallibaum was ejected, the second time he failed to make it to the final whistle at Sporting Park this season.

Angry to be down a goal, the Impact's second-half response was swift and decisive.

"Everyone's reaction on the field was that it wasn't a penalty," Warner said. "I don't know what it looked like on the television, but yeah we felt aggrieved to go in at 1-0 and there was a little bit of emotion in the locker room when we came out and I think everyone saw that."

Sporting KC right back Mechack Jerome picked up a yellow card near the end line for a reckless challenge against Felipe Martins.

On the ensuing free kick, Nyassi collected a rebound then drove a shot through traffic that knotted the game in the 47th minute.

Six minutes later, Sporting KC's defence struggled to clear a cross from forward Marco Di Vaio. The ball pinged around the penalty area, including a bicycle-kick cross from Martins, before coming to rest at Warner's feet after Peterson Joseph whiffed on a chance to clear the ball.

With one swift strike, the Impact were in front on Warner's first career goal and that 1-0 halftime lead seemed a distant memory.

"It's a highly emotional game and we tried to manage that," Biello said. "You need to manage your emotions in different moments, and I think my team did a good job managing their emotions and coming out in the second half and scoring two goals. They transmitted their energy in the right places and we were able to get the win."

It was Warner's first career goal.

"I'll take it, a game winner on the road isn't too bad," Warner said. "I was super-happy and proud of the team tonight, we did well to fight back and overcome some circumstances, some calls didn't really go in our favour so it was a huge game."

That is especially true after Montreal, which was outshot 19-7 and only controlled 42.4 per cent of the possession, played the final 16 minutes down a man when Nesta was ejected for head-butting Bieler in the 74th minute.