US Open champion Angel Cabrera wanted to beat an elite field of major champions at the PGA Grand Slam of Golf, but it did not escape the big-hitting Argentine that this was an exhibition.

That explains why he hit driver at every turn, with mixed results.

It put him in dire trouble on the opening hole of the final round, leading to a triple bogey that left him five shots behind. And it rescued Cabrera at the end of an exciting afternoon at Mid Ocean Club, with two booming drives on the par-five 18th.

One led to an eagle that put him in a play-off with British Open champion Padraig Harrington.

The other led to a two-putt birdie for an unlikely victory on Wednesday.

"I trust my driver very much," Cabrera said. "And I thought it would be nice here to show off a little bit, to show everybody how nice and how far I hit my driver."

Indeed, some 7,000 fans — that's about 10 percent of the population on Bermuda — gasped when Cabrera pounded the ball off tee.

Even more breathtaking was his finish.

Cabrera finished birdie-eagle to atone for his triple-bogey start, giving him a two-under 68 to force a play-off with Harrington. He beat the Irishman with a birdie on the third extra hole to get the Grand Slam off to a great start in its new home in the Atlantic.

"The only thing I can say is it was complicated after the first hole, and I was able to come back," he said. "And that was a great thing."

Harrington is never speechless, but he was searching for words after closing with a 69, not making a bogey over the last eight holes.

He had not trailed in the Grand Slam for the 32 consecutive holes until he found a bunker off the tee at the par-five 18th on the third extra hole, barely got the next shot out and was still four feet away for par when Cabrera tapped in the winning birdie.

"I wasn't happy with any part of my game," Harrington said. "I worked really hard to keep myself in that position to stay in front. It's a lot easier of course when you're chasing rather than leading out there. I was beaten by a birdie-eagle. It was a great finish by Angel."

Not many thought such an entertaining finish was possible. Harrington led by four shots with 11 holes to play and appeared to hold off a revolving door of challenges from the other three players in the field.

Jim Furyk, the replacement when PGA champion Tiger Woods skipped the event for the first time he was eligible, had momentum on his side until he tried to hit a shot he didn't have out of the bunker, knocking it over the green and into the bushes for a triple-bogey eight.

Masters champion Zach Johnson, seven shots behind with 10 holes to play, made up five shots in five holes but couldn't get any closer.

"I couldn't keep track of who was behind me," Harrington said.

Cabrera, who rallied from his atrocious start to catch Harrington with an eagle on 11th hole, figured to be the least of Harrington's worries when the Argentine made a sloppy bogey on the 16th after driving some 50 yards short of the green.

"I told my caddie we had to make 2-3 to have a chance," Cabrera said.

He got the two with an eight-iron into about 10 feet on the 17th as Harrington made par. And the three came from his eagle on the 18th, a booming drive and a four-iron that caught the slope just right and rolled to four feet behind the hole. Harrington two-putted for birdie for only the third play-off in the 25-year history of this event, and the first since Woods beat Vijay Singh in 2000 at Poipu Bay.

The play-off holes were the 17th and 18th, which didn't bode well for Harrington.

"It was hard to go into a play-off where he had just gone birdie-eagle," he said. "I didn't see any advantage I had."

Both missed the 18th green and made pars, and Harrington got up-and-down at the 17th to keep the play-off going. Cabrera pounded another tee shot on the third extra hole at 18, hit a four-iron to 18 feet. He needed only two putts for birdie and the victory after Harrington hit into a deep bunker off the tee and still had four feet left for par when it ended.