Brimmer's marvellous, dipping half-volley from outside the box, after Jamie Young had punched a corner clear, in the 74th minute at AAMI Park proved the difference in a clash that had plenty of aggression but few quality chances.

Crucially, it hands Tony Popovic's Victory a one-goal advantage ahead of Saturday's reverse fixture at the same venue, as they eye their first grand-final appearance in four years.

"It was a tough semi-final. It's what you expect, it was a real battle," Popovic said.

"We had to be patient and it took a fantastic goal to do it but at half-time in a two-leg match, we've got the slight advantage."

Popovic hailed breakout star Brimmer for again stepping up in a big moment.

The 24-year-old previously claimed the Mark Viduka Medal as man of the match in Victory's FFA Cup final win and has four goals in his past five games.

"Jakey is doing something now that probably he needed in his game," Popovic said.

"He's always assisted goals but now he's scoring and he's scoring in big games.

"We're very happy with how he's playing and hopefully he can produce another special moment on Saturday.

"He's always had the talent and now he's a lot more consistent in his play.

"He's one of the players in our squad that didn't miss (pre-season) training. He wanted to be the best every day.

"When you work that way and you have the talent Jakey has, the rewards can follow."

There was controversy with United arguably unlucky not to receive a penalty in the fifth minute when Jason Davidson went into Lachie Wales' back.

"We all saw it. The referee obviously didn't see it. The assistant referee didn't see it, I don't know how. But the VAR missing it has happened to us all season so I expected the VAR to miss it," United coach John Aloisi said.

"... Anyone that understands the game will know that's a clear penalty.

"There's no intent to play the ball. He's pushed him from behind.

"That's disappointing because when it's so clear, you expect if the referee doesn't see it ... then help him."

On the whole, the United boss was pleased, especially given they were coming off a three-day turnaround compared to Victory's nine days between games.

United dominated early in the first half and in the eighth minute Victory goalkeeper Ivan Kelava did brilliantly to bat away Aleksandar Prijovic's near-post header.

Aloisi's side had several half-chances to equalise after Brimmer's goal.

"We limited them to a few chances, if any, and they had to score a special goal to win the game," Aloisi said.

"To be honest, we're well and truly in this tie. This is the first half, we're 1-0 down."

Australian Associated Press