Audrey Belzile whacked a rebound out of midair 9:18 into overtime to give Team Quebec the golden goal it needed and a 2-1 victory over Team Ontario.
Belzile was in the right place at the right time to bang in the rebound when Alyson Matteau's wristshot was stopped by Ontario goalie Julia Vandyk at CN Centre.
The goal came on the power play. Ontario defenceman Lindsay Eastwood put her team in a hole 8:09 into OT when she nailed Belzile at the blueline and made contact with her head, an automatic four-minute double-minor penalty.
It was Quebec's first-ever win in the seven attempts since women's hockey became part of the Games in 1991. Ontario had won the tournament six times.
Ontario outshot Quebec 42-24, 11 of which came in overtime.
Kristen O'Neill tied the game 1-1 at 16:40 of the third off an offensive-zone face-off win. The 16-year-old from Oakvile, Ont., took a pass in the slot from linemate Lindsay Agnew and ripped a low shot into the net past Quebec goalie Maude Trevisan.
That came 15 minutes after Victoria Eymard broke a scoreless deadlock on a Quebec power play 1:40 into the third period.
Sarah-Eve Coutu-Godbout took a shot from the faceoff circle that hit an Ontario stick and ricocheted off the end boards to Eymard, who unleashed a backhand shot while standing behind the goalline and the puck bounced in off the leg of Vandyk.
The game featured great goaltending at both ends, great defensive plays from out-of-position defencemen to catch up to fast-breaking forwards and plenty of hold-your-breath goalmouth scrambles. The crowd of about 3,000, certainly got its money's worth.
Ontario left winger Rhyen McGill had the best chance of the first period 12 minutes in, a backhander that forced Trevisan to make a terrific kick save. Ontario failed to capitalize on four minor penalties handed out to Quebec in the first period.
Ontario's power play nearly connected at the end of the second period but McGill was left shaking her head again when she took a whack at loose puck in front that Trevisan stopped with her leg while spinning on the ice.
Meanwhile, in the bronze-medal game, Malia Schneider scored two first-period goals and Sarah Lecavalier added one more on a power play in the second period to stake Alberta to an early lead and they hung on to defeat Saskatchewan 4-3. Dayna Owen turned aside 29 of 32 shots to earn the win for Alberta, the defending champions, who were outshot 32-29.