Worse yet was missing a short par putt on the 16th that really crippled his chances.
'It was more difficult to be two behind on the 17th tee than five behind on the second tee,' Cabrera said. 'There's a lot of golf left on the second tee -- not on the 17th.'
He made the most of the little golf he had left, finishing birdie-eagle to close with a 2-under 68 and force a playoff with British Open champion Padraig Harrington (69), then beating the Irishman with a birdie on the third extra hole.
Both finished at 4-under 136.
Some 7,000 fans at the Mid-Ocean Club -- that's about 10 percent of the population of Bermuda -- were treated to an exciting finish they never saw coming. Harrington led by four shot with 11 holes to play and appeared to hold off a revolving door of challenges from the other three major champions 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 8.
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 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 2 with an 8-iron into about 10 feet on the 17th as Harrington made par. And the 3 came from his eagle on the 18th, a booming drive and a 4-iron that caught the slope just right and rolled to 4 feet behind the hole. Harrington two-putted for birdie for only the third playoff in the 25-year history of this event, and the first since Woods beat Vijay Singh in 2000 at Poipu Bay.
The playoff holes were the 17th and 18th, which didn't bode well for Harrington.
'It was hard to go into a playoff 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 playoff going. Cabrera pounded another tee shot on the third extra hole at No. 18, hit a 4-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 4 feet left for par when it ended.
For the first exhibition in the silly season, these guys were all business.
'I wouldn't have liked to be second here,' Cabrera said.
Cabrera, who held off Woods and Furyk at Oakmont to capture the U.S. Open for his first major, earned $600,000.
Furyk finished with a flurry, making four birdies on the last five holes. That wasn't enough to recover from his triple bogey, but he closed with a 67 to finish third at 138 and earn $250,000.
'I fought back pretty good, but 11 definitely took my chances away,' Furyk said.
Johnson needed an eagle on the 18th for any chance of a playoff, but his approach rolled off the green, he chipped to the back of the green and three-putted for a bogey. That gave him a 68 to finish at 139, with last place worth $200,000.
'I just didn't want to finish fifth,' Johnson said.
Harrington's only big mistake came at the ninth, when he hooked his tee shot into the bushes. Despite getting plenty of directions from fans across the fairway, he never found his ball and wound up with a double bogey.
That put some drama into the back nine, setting up a big finish and an unlikely victory for Cabrera.
'The only thing I can is it was complicated after the first hole, and I was able to come back,' he said. 'And that was a great thing.'
To say it was complicated might be an understatement.
Cabrera picked the wrong line off the tee and was deep in the woods, his only hope squeezing it under the branches about 20 yards out of trouble. But his second shot hit a tree and was headed for his leg when it clipped a branch and narrowly missed him, sparing him a two-shot penalty.
He took a penalty drop for an unplayable lie, hacked that out about 10 yards, then got to the green and took two putts for a 7. Then came a three-putt bogey on the second hole, and he was fortunate it wasn't worse. He scramble for par on the third, and after chunking a wedge some 20 yards short into a bunker on No. 5, again escaped with par.
Cabrera had few complaints the rest of the way, especially with the finish.