Karly Roestbakken is still more than two years from her first legal drink but the Canberra United teen handed Melbourne City their first ever loss.
The cashed-up Melbourne club owned by an international sporting conglomerate was undefeated through their 18 games in the W-League and the two youngest players on the park – Roestbakken and Nickoletta Flannery – combined to bring them down.
At 15 years and 10 months, Roestbakken became the second youngest player to score in the league's history and United now sit just two points off the top of the table.
The win was made even more special with a number of the players in green succumbing to a stomach illness.
American import Stephanie Ochs was forced off the field at half-time, which brought junior Matilda Roestbakken into the game.
United midfielder Jenna McCormick was confident her side would be the first to take points off City and it was her goal in the 49th minute that opened the scoring.
She rose above the pack to head home the goal from the corner delivered by Grace Maher.
However, the defending champions weren't behind for long and responded four minutes later with a powerful strike by Beverly Goebel into the top corner of the net.
Canberra then dominated possession and had a number of chances to again go in front.
And in the 82nd minute Flannery presented a square pass for Roestbakken, who calmly converted to give United a 2-1 lead.
United coach Rae Dower said her team had "their backs against the wall" but they were confident they could travel to Victoria and reverse the loss to City from round one.
"The girls showed in the first round that whilst they hadn't played together before we did stick to them and we probably played better in patches and created a lot more opportunities in that first game," she said.
Dower said Roestbakken's goal was no fluke.
"She made that run at the back post repeatedly over that 45 minutes, she must have made up to 10 in a row and just the willingness to keep running and keep being in that position."
Roestbakken admitted she had dreamed of such a moment but never believed it would happen.
"When that went in I was so stoked I just couldn't believe it," she said.
"I was determined to try and get in there and make a difference and just determined to score, I just wanted to put that in the back of the net."
W-LEAGUE ROUND SIX
Canberra United 2 (J. McCormick 49', K. Roestbakken 83') bt Melbourne City FC 1 (B. Goebel 53')
