Australian Jason Day birdied the final three holes to win the 2015 RBC Canadian Open on Sunday, spoiling David Hearn's bid to become the first Canadian winner in 61 years.

Day made a 20-foot putt on the par-5 18th to finish up his final round of 4-under 68 and claim the one-stroke victory over American Bubba Watson, who shot a 3-under 69 during the final round.

Hearn went into the final round, holding a two shot lead over Watson and Day, but couldn't hold off the charge from his competitors finishing with an even-par 72 on Sunday.

Hearn birdied his first two holes, but he would give those two shots back before the end of his front nine. He finished with five straight pars and went into the final hole needing an eagle to tie Day for the tournament lead.

His second shot went into the bunker meaning that Hearn would have to hole out to force the playoff, but it wasn't meant to be.

Moose Jaw-born Adam Hadwin put together a strong final round as he shot a 68 during to finish tied for seventh. He played his first four holes on the day at four-under par, but would bogey seven and eight before having an up and down back-nine that included four birdies, a bogey and a double bogey.

Day took home $1,044,000 for his win, while Hearn cashed a cheque for $394,400 and Hadwin picked up a $174,725 payday.

Weyburn's Graham DeLaet was forced to withdraw from the tournament during the second round on Friday.