Rookie Andrew Wenger didn't waste his chance to show what he could do when he gets a chance to score.

The 21-year-old leapt in the air to head in a goal on a set play off a corner kick just before half time to help the Montreal Impact to a 2-0 Major League Soccer victory over the visiting Philadelphia Union on Saturday night.

The top pick in the SuperDraft got the start because designated player Marco Di Vaio was in Italy, where a prosecutor has called for the former Bologna star to be suspended one year for failing to report alleged match fixing in a scandal that has shaken Italian soccer.

Wenger looked ready to take up the challenge.

"I don't think the replacing Di Vaio thing is much of a story," said Wenger after his fourth goal in 14 MLS games. "I've played out there by myself before.

"It's another game where, as a rookie, I'm trying to prove I can play in this league and keep progressing."

Midfielder Felipe Martins added an insurance goal in the 78th minute of a match in which the Impact did not play nearly their best but still came away with three points.

The Impact (9-13-3), who are 8-3-2 at home, moved past the Columbus crew into sixth place in the Eastern Conference and opened a seven-point lead on eighth-place Philadelphia (7-11-2). However, both of those rivals hold five games in hand on Montreal.

'I can't for the life of me figure out how we're not up a man for the last 22 minutes. It's unfathomable to me.'— Union coach John Hackworth, disputing red card handed Jack McInerney

Shoving match

The Impact may get more bad news this week as central defender Nelson Rivas was sent off along with Union forward Jack McInerney in the 69th minute after a shoving match, leaving both clubs with 10 men to finish the match.

Replays showed Rivas head butting the Philadelphia player, so he may get more than the automatic one-game suspension for a red card, although there was embellishment on both sides of the melee.

"One's a head butt and one's a very innocent push," said Union coach John Hackworth. "I can't for the life of me figure out how we're not up a man for the last 22 minutes.

"It's unfathomable to me. I looked at the video. Jack doesn't even really push him."

With Rivas out at least for the next game Aug. 12 at New England, Matteo Ferrari will likely move back to the central defence after playing a rare match at left back. He felt bad for Rivas, a fellow former Serie-A player.

"We are all human," said Ferrari. "Sometimes you can lose your mind and do something wrong.

"That happened with Nelson but he's the first guy who is really sad for what happened. I didn't see it. I heard it was a head butt, so we will see what MLS will decide. I hope we don't lose him for a long time."

The win avenged a 2-1 loss in Philadelphia on July 14 on a Carlos Valdes goal in stoppage time. It was Montreal's second victory in a row after a 3-1 decision over New York a week earlier.

3rd shutout

Goalkeeper Donovan Ricketts and the team got its first clean sheet since a 2-0 win at Kansas City on May 5, and only its third of the season.

"The good thing is we didn't allow a goal, that's the first step," said Ferrari. "But I think we didn't do well as a team.

"We played much better against New York. We're happy we won but if you see how we won, we didn't do well. We have to do better. If we play like that I don't know how many games we can win."

The Union missed two glittering chances in the first half as Lionard Pajoy hit a post and McInerney was stopped from point blank off a corner kick. Montreal got a goal just before the intermission.

Justin Mapp played a corner kick back to Patrice Bernier, who chipped the ball into the middle for Wenger to make a leaping header that pushed the ball over Zac MacMath and under the crossbar.

Felipe struck in the 79th minute, thrusting forward to head in Hassoun Camara's cross.

"Those two missed chances came back to haunt us," said Hackworth. "Then we opened the second half and have a great combination play through the middle and miss another one.

"If you don't [score] you can't win."