Of the five games in the season-defining 15-day stretch that started for the Union on Saturday night, the home matchup with the Montreal Impact was the one they could least afford to lose.

Not only did they lose it, they lost it in a 4-1 blowout.

"It's a total team performance that was not good enough — coaching staff, players, everybody is included in that," manager Jim Curtin said. "I'm debating whether to even watch the tape, because it was just a disappointing performance and it wasn't us."

Early on, the Union (12-12-4, 40 points) looked in good shape. In the 11th minute, Media native Auston Trusty scored his first professional goal, thundering home a header after some corner kick trickery by Borek Dockal and Haris Medunjanin.

Dockal's assist was his 15th of the year, giving him the league lead and tying the Union's single-season record set by Cristian Maidana in 2015.

Alejandro Silva equalized in the 28th for Montreal (12-14-3, 39 points), capitalizing on a lightning-fast breakaway after Fafa Picault slipped. Impact star Ignacio Piatti pounced on the loose ball, sprinted upfield, and sent Silva on his way to do the rest. Andre Blake came way off his line to try to cut off the play, but ended up helpless.

Montreal went ahead in the 39th with another goal almost out of nowhere. Quincy Amarikwa spun off Ray Gaddis at the edge of the 18-yard box and blistered a low shot that Andre Blake could only parry. Saphir Taïder pounced and finished from close range.

Amarikwa extended the lead in the 63rd, with a scrappy finish of a sharp cross from Germantown Academy product Daniel Lovitz.

Silva and Piatti sealed the win in the 74th, teaming up for another counter-attack clinic.

A Talen Energy Stadium crowd that was one of the bigger of the season was nervously quiet. There were even a few boos, and taunts that the team is winless since introducing its first ever mascot last Tuesday.

It was hard to blame them. With a game at red-hot Seattle coming Wednesday, the momentum gained over the last few weeks seemed to be disappearing in a hurry.

"We all know we're a good team, and it's almost a good thing to show that we're not above having to play 100 percent every game," defender Jack Elliott said. "We have to go out there and compete for every ball in every minute of the game. … Over that period of August we limited mistakes a lot, and today we had a few and it cost us."