The 51-year-old Senior, a regular on the Champions Tour, made a 10-foot birdie putt on the 18th hole in regulation for a 1-under 71 to match Ogilvy, the Australian Open winner last week in Sydney, at 12-under 276. Ogilvy finished with a 66.
Both players parred the 18th hole on the first hole of the playoff, and Ogilvy three-putted for a bogey on the second extra hole to give Senior his third Australian PGA title.
“What a great way to finish the year,” Senior said. “Geoff hit a pretty indifferent iron shot into 18, and we all know how difficult it is to get down from that area. But I would have rather made my (birdie) putt instead of Geoff three-putting, but that’s what happens.”
Ogilvy said he was disappointed with the finish but not with his play overall in the past two weeks.
“That’s the best way I’ve finished a year in a long time,” Ogilvy said. “But to be honest, I never really felt that I was in this tournament until Sunday. And I never thought my 12 under would hold up for a playoff.”
Ogilvy had to wait at least an hour – “I hit a lot of balls on the range” – between his finish and Senior completing his round in the final pairing.
Twenty-four players finished the round Monday after heavy rain delayed play Sunday.
Australians Nick O’Hern (69), Peter Fowler (71) and Andre Stolz (71) tied for third at 11 under. Stolz bogeyed the 18th after hitting his tee shot into the water.
American Bobby Gates, who led by a stroke after the third round, bogeyed two of his final nine holes Monday and finished with a 74, leaving him two strokes out of the playoff
Ogilvy resumed play Monday on the 14th hole, and birdied that hole and No. 16. Senior, ahead by one when play resumed, bogeyed his first hole of the day – the 10th – after his tee shot in pouring rain Sunday left him in the trees.
Defending champion Robert Allenby finished four strokes back after a 70.
Gates, playing the Coolum course for the first time, tried to be diplomatic Sunday when play was called despite a tough officiating decision that had forced him to hit an awkward shot out of a bunker that was nearly flooded by rain. He ended up bogeying the hole.
“I’ve never played where it’s gotten to this point before, but I understand they want to try to get it in,” Gates said.
Senior, who said he felt Gates got a bad decision on his bunker shot, said the last three holes that he and Gates played were extremely difficult, and “the 10th tee was actually underwater when we got there.”
“I was just a little disappointed that the round wasn’t called a little earlier,” Senior said. “A lot of guys were suffering out there, not so much with the rain, but when the fairways become so water-logged that you can’t actually hit golf shots that’s when it should be called. … Poor old Bobby Gates. The bunker was just riddled with water on the ninth hole there and had to play his shot and he could have made 4 if he just putted the hole. But when the course is unplayable, the day should be called and that’s it.”