Players, fans and officials were furious after Canberra goalkeeper Lydia Williams was seemingly obstructed in the lead-up to Jasmyne Spencer's 61st minute winner for Sydney FC at McKellar Park on Sunday.

Dower was forced to bite her tongue as referee Casey Reibelt decided to let Kyah Simon's contact with Williams go unpunished.

"If I told you what I really think, my credit card would have to be there and my wallet's not deep enough to cop that fine," Dower said.

"We saw it live, a number of you have seen it again.

"You'll see it played back on the TV review, so you make up your own minds."

Additional assistant referees were placed on both goal-lines for the W-League and A-League finals to prevent blunders being missed.

But incredibly, all six officials waved play on as Simon collided with Williams when a high ball from Princess Ibini was crossed into the box.

Spencer tapped the goal away despite the protest of Williams and Canberra captain Nicole Begg.

"If (Williams) had two arms and could jump ... you saw the save she made on the goal-line," Dower said.

"She can jump when she's not being fouled and can make the save."

Canberra spurned plenty of golden chances in the second half to level the score, the best falling at the feet of Ashleigh Sykes in the 81st minute, but ultimately the game slipped away.

A superb regular season resulting in eight wins, two draws and two losses finished a game too soon.

The Sky Blues will now prepare to face either unbeaten juggernaut Melbourne City or Brisbane Roar in next Sunday's grand final while Canberra reflect on what could have been.

Canberra was attempting to become the first team in the eight-year history of the W-League to win back-to-back championships.

"I think it's important we learn from this and we do have a lot of young girls in the squad," Begg said.

"One thing we need to change going into future seasons is being able to put teams to bed earlier and we haven't done that.

"In the early seasons we were always the underdog and it was easy to come out and fight, but when we've been touted as the best, I think we've struggled a little bit.

"I think that's a cultural thing we need to address."

Canberra's cause wasn't helped when they had Mexican international Veronica Perez unavailable because of international duty with Matildas representative Caitlin Munoz taking her spot in the midfield.

"Three weeks ago we knew we were going to be without her, we planned for that and her not being there didn't change the course of the game," Dower said.

"Maybe her creativity up top, we probably lacked that a little bit.

"At the end of the day, we had enough chances to win two or three games, and we didn't capitalise on them today."

While Canberra controlled 60 per cent possession in the opening half they couldn't capitalise on their chances to breach Sydney's goal.

Some of that credit can go down to the splendid work of Sydney FC goalkeeper Michelle Betos, an acrobatic tip over the bar denying Sykes from opening the scoring.

At the other end, pace down the flanks and the ability to create chances on the counter attack kept the small army of Sydney FC fans interested.

City will host the Roar at AAMI Park on Monday for the right to face Sydney FC in the grand final.

W-League semi-final: Sydney FC 1 (Jasmyne Spencer 61') bt Canberra United 0 at McKellar Park on Sunday. Crowd: 2131