Marco Fabián has taken a lot of criticism from Union fans this year, for not living up to expectations put upon him as the Union’s biggest-ever signing.

On Sunday night, the critics finally had to eat some crow.

So what if Fabián’s game-winning goal was something of a fluke, given the big deflection it took on its way into the net. Watch the replay just once and you’ll know he was shooting.

It was, plain and simple, the biggest goal in Union history, and it was scored by the player who was signed for exactly that purpose.

Has his year been perfect? No, and he’ll be the first to admit it — as he did to The Inquirer last week. He hasn’t fit in tactically as well as the Union’s coaching staff hoped, which is a big part of why he started just two of their last eight games. Fabián didn’t enter the historic 4-3 comeback win over the New York Red Bulls until late in the first extra-time period, and if the game hadn’t gotten there, who knows if he’d have played at all?

But the game did get there, and when the moment came, he rose to it.

“Look, if people want to criticize Marco, they’re wrong,” Union manager Jim Curtin said after the game. “People should criticize me because I’m the one that didn’t put him in the game. And when he was called upon he delivered."

That wasn’t just Curtin publicly defending one of his players, as he so often does. That was genuine.

“He wants to win here in Philly, he wants to make a special play like he did tonight to win us the game, and he’s a professional," Curtin continued. “While he’s disappointed, I’m sure, with me for not being in the starting lineup, he’s always been professional, respectful. … If people want to be critical of him, the finger should point to me.”

Curtin’s postgame news conference ran twice as long as usual, commanding so much interest that Fabián was showered, dressed and gone before Curtin left the podium. It took some other players longer to leave, especially captain Alejandro Bedoya, who was banged up so badly that he was subbed out of a game for the first time all year.

“I know how hard it’s been for him and what he’s been dealing with,” said Bedoya, who rooms with Fabián on road trips and gave Fabián a big hug when he scored. "I just told him, ‘That’s why you make a difference,’ and ‘Just leave it all out there.’ "

Fabián did more than just score a goal on Sunday. He played a pretty big role in helping the Union seal the win in the closing minutes. He had some key stretches of possession, recorded two successful dribbles past opponents and completed 7-of-9 pass attempts.

“He always kept his head cool, and he came in and he contributed like that,” fellow midfielder Haris Medunjanin said. “He’s that kind of player that he can give us something extra, you know, and that’s what he showed us today.”

While Fabián hasn’t always been popular among Union fans, he is quite popular in the Union’s locker room. Curtin, Bedoya, Medunjanin, Andre Blake and Fafa Picault all attested to that Sunday night. Yes, Fabián has missed a team meeting or two, and there were consequences. But when that many veterans stick up for a teammate, it matters.

“It’s unfortunate that we weren’t able to get more from him this season, but tonight just goes to show that he is a big guy who has been in big games, and who knows what it’s about," Blake said. “He came in and did great for us tonight.”

Fabián will probably be gone after this season, because of the aforementioned tactical misfit. Union sporting director Ernst Tanner smartly structured Fabián’s contract from the start as a one-year deal with two years of club-held options, allowing the team to see if he’d work and cut ties if he didn’t.

The end might come Thursday in the conference semifinal at Atlanta United (8 p.m., ESPN2 or ESPN Deportes). If the Union are able to upset the reigning MLS champions, the end will come some time later.

Whenever it happens, there can be no doubt now that Fabián delivered for this team.

“A night I’ll never forget,” Fabián wrote on Instagram. “This is what everyone dreams of in football ... Thank you, Philly.”

“He gave everything for the club tonight, and he sent 18,000 people home very happy because of his performance," Curtin concluded.

Some of the critics might just have been among them.