The Union took sole possession of second place in the Eastern Conference with a commanding 4-1 win over the Montreal Impact Sunday night, in a game played at Red Bull Arena in Harrison, N.J., because of U.S.-Canada border restrictions.

Though the final score was lopsided, the game’s early stages were ugly. The Union (7-2-3, 24 points) gave up the first goal in the fifth minute after Warren Creavalle, Mark McKenzie and Montreal’s Orji Okwonko got tangled up just outside the 18-yard box, and Okwonko drew the foul. Romell Quioto threaded the ensuing free kick through a hole in the Union’s wall and out of Andre Blake’s reach.

Quioto introduced himself to McKenzie in the 12th minute with a few shoves — then a forearm to the head. The swing initially only drew a yellow card from referee Marcos de Oliveira, and Jim Curtin’s shout of, “That’s an elbow to his head!" was easily heard on the TV broadcast. After a long delay, the video replay booth summoned de Oliveira to the sideline monitor, and he correctly judged the foul worth a red card.

Montreal (5-6-1, 16 points) has a long history of stealing results down a man, and Curtin has witnessed a few of them in person. So there was ample relief when Alejandro Bedoya smashed in the equalizer in the 22nd from close range, after Andrew Wooten trapped a Matt Real cross into Bedoya’s path. That play had its share of controversy too, as the replay booth took a long look at whether Wooten’s trap involved a handball.

Przybylko put the Union ahead 2-1 in the third of five minutes of first-half stoppage time, meeting another terrific Real cross with a perfect running header at the back post.

Curtin upped the attacking ante at halftime, withdrawing Creavalle for Anthony Fontana and changing the Union’s formation from the usual 4-4-2 to a 4-3-3: Brenden Aaronson, Przybylko and Wooten on the forward line, and Fontana in front of Bedoya and Monteiro in midfield.

The move paid dividends just 69 seconds after kickoff. Mark McKenzie played an outstanding pass through Montreal’s defense, then Aaronson burst through the back line to claim the ball and set up Przybylko to score.

“When we got in at halftime, as a staff we said that there was two positive things: the first thing was that we were winning 2-1, and the second thing was that we couldn’t play worse,” Curtin said. “To the players' credit, they really responded at the start of the second half and killed the game off pretty quickly.”

Fontana added his tally in the 65th with a thump from the edge of the 18-yard box after McKenzie headed down a Mbaizo cross and laid it off.

With the game secured, Curtin had an opportunity to sub out his workhorses ahead of a short turnaround to visiting FC Cincinnati on Wednesday. He only took it in part. Przybylko exited for Sergio Santos in the 72nd minute, but Bedoya didn’t leave until the 87th. Aaronson left at the same time, with Jack de Vries entering and Cole Turner making his MLS debut.

“Could we have done Ale a little earlier? Maybe," Curtin said, "but the demands of the game were such, because we had so much of the ball, that the guys didn’t have to put a ton into it. … There’s an opportunity to give Cole his debut — the kid works really hard in training — so that factors in as well.”

Curtin had bigger goals in mind, too.

“You guys know how tight it gets at the end of the year, and goal differential will play a role [in] whether you perhaps maybe host a home game, or you go have to go on the road,” he said. “In those top four spots, every point’s going to matter, every goal matters. You weigh all those factors and then you sub and adjust accordingly.”