A double to Matildas striker Michelle Heyman, a maiden goal from Jenna McCormick and Veronica Perez's successful penalty in injury time guided Canberra to a fourth straight win.

While the unbeaten Melbourne City remains the benchmark in the competition with a perfect seven from seven, second-placed Canberra is building the momentum it needs in the run into the finals.

Canberra coach Rae Dower said her side had plenty of opportunities to put the result to bed before it finally found a third goal late in the game.

"I thought the first half was very dominant, but only two goals so that kept (Adelaide) in the game," Dower said.

"It probably took us a little bit longer than we liked to kill the game off. We want to be better at converting those chances and today there was some really great movement on and off the ball."

It was also the fifth straight game Canberra in which hasn't conceded a goal since its 4-2 loss to City at Central Coast Stadium on November 8.

Canberra's back four of Ellie Brush, Nicole Begg, Rebecca Kiting and Emma Checker received great support from midfielder Kendall Fletcher.

Matildas goalkeeper Lydia Williams had another superb performance in front of national team coach Alen Stajcic.

"It's great to create and score some goals up that end of the field but another important part of that is Emma and Brushy at the back, along with Nic and Bec and Kendall, did a lot of work defensively," Dower said.

"The back five were really solid today and had another clean sheet."

Canberra made the best possible start when Heyman opened the scoring in the ninth minute.

Heyman benefited from some wonderful lead-up play from Ashleigh Sykes, who found space down the right-hand side and delivered a delightful cross to Perez.

Adelaide keeper Kaitlyn Savage stopped Perez's stinging shot, but could only parry it into the path of Heyman, who converted from close range.

Sykes was again involved in Canberra's second goal on 15 minutes, the Matildas international chipping the ball into the six-yard box.

The chance fell at the feet of McCormick and the Canberra recruit found the net for the first time in her W-League career against her old side.

Canberra dominated the play, but it took until the 84th minute when Heyman sealed the result with a cracking strike on an acute angle off an assist from substitute Julia De Angelis.

Mexican international Perez converted a penalty in injury time much to the delight of the 887-strong crowd to cap a wonderful afternoon.

Canberra completes its run of three straight home games when it hosts Melbourne Victory next Saturday, December 19.

CANBERRA UNITED 4 (Heyman 9, 84, McCormick 15, Perez 90+3) bt ADELAIDE UNITED 0 at McKellar Park on Saturday. Crowd: 887.