A goal in the last seconds of injury time has enabled Sydney FC to steal a 4-3 win over a luckless Canberra United in steamy conditions at Leichhardt Oval.
The match appeared headed for a draw after a wonder strike from American import Nikki Washington locked things up at 3-3 with six minutes left.
But the Sky Blues had other ideas, launching a raid deep into time added on.
Skipper Kyah Simon made a searching run down the left and laid the ball off to substitute Emma Kete who fired home from near the penalty spot.
The match, played at a hectic pace despite the heat, barely had time to re-start before the referee blew for full-time.
Twice United found themselves behind but fought back bravely.
Early goals to skipper Simon and Sam Kerr gave FC a 2-0 advantage before Georgia Yeoman-Dale and Hayley Raso restored parity.
Simon put the Sky Blues ahead again in the 77th minute, slotting a penalty following an earlier miss from the spot.
Enter US youth international Washington.
Brought on as a second-half substitute, she hit a speculative shot from out near the right sideline and wheeled around in delight as it floated into the top left-hand corner of the net.
Sydney goalkeeper Sian McLaren did get a hand to the ball and will feel she should have done better but the audacious strike was just reward for a Canberra unit that fought all the way just days after returning from the Women's World Championship in Japan.
They will feel they should have at least taken a point back to the capital after overcoming a dreadful start.
The hosts took just five minutes to hit the front, skipper Simon keeping her cool to slot home the opening goal on five minutes.
The Sky Blues doubled their advantage 13 minutes later when Kerr's header from a pinpoint Nicola Bolger cross left keeper Mackenzie Arnold stranded.
Canberra were being torn apart but kept their composure to slowly work their way back into the game.
Their reward came just past the half hour, Yeoman-Dale slamming home from close range after McLaren failed to clean up a low cross.
It was Yeoman-Dale's first W-League goal for Canberra and it could not have arrived at a better time.
But just a minute later the defending champions' comeback appeared dead in its tracks after Simon was shoved in the back inside the box.
The referee rightly pointed to the spot but Simon's attempt was well blocked by Arnold diving to her left.
Canberra prospered shortly after that let-off, equalising just after the half-time break.
Raso timed her run perfectly to get to a lovely through ball first and poke the ball past the advancing McLaren.
Washington was then introduced to the game and made an immediate impact before United were stunned by Sydney's late, late winner.
Sydney FC 4
(Simon 4, 77, Kerr 16, Kete 94)
Canberra United 3
(Yeoman-Dale 32, Raso 60, Washington 84)
Sydney FC: McLaren, Polias, Ralston, Kerr, Bolger, Rollason, Crummer, Kennedy, Perry, Simon (c), Billson (Kete 64)
Res: Foord, Logarzo, Kete, Khamis
Canberra United: Arnold, Cooper, Yeoman-Dale (Washington 63), Munoz, Brush, Raso, Heyman, Sykes, Brown (Walters 60), Hingst, Bisset.
Res: Walters, Shipard, Burke, Washington