SAN DIEGO — With a throbbing knee and a pounding heart, Tiger Woods made one last improbable escape today and won the U.S. Open in a 19-hole playoff over Rocco Mediate, his 14th career major and maybe the most amazing of them all.

One shot behind after a collapse no one saw coming, Woods birdied the 18th hole to force sudden death at Torrey Pines against a journeyman with a creaky back who simply wouldn't go away.

But that one extra hole was enough to doom Mediate, trying to become the oldest U.S. Open champion at 45 years, 6 months.

He put his tee shot in the bunker at No. 7, knocked his approach off a cart path and against the bleachers, chipped some 18 feet past the hole and missed the par putt.

On the verge of one of golf's greatest upsets, Mediate instead became another victim.

"Great fight," Woods told him as they embraced on the seventh green.

Woods, who delivered so many spectacular moments over four days along the Pacific bluffs, only needed a two-putt par to win the U.S. Open for the third time, and the first since it last was held on a public course at Bethpage Black in 2002.

It capped a remarkable week for the world's No. 1 player, who had not played since April 15 surgery on his left knee and looked as though every step was a burden. But the knee held up for 91 holes, and the payoff was worth the pain, even if doctors had warned him that he risked further injury by playing the Open.

"I'm glad I'm done," Woods said. "I really don't feel like playing anymore. It's sore."

Woods joins Jack Nicklaus as the only players to capture the career Grand Slam three times over.

Mediate's odyssey began two weeks ago when he had to survive a sudden-death playoff simply to qualify for this U.S. Open. Even more unlikely was going toe-to-toe with Woods — whom Mediate referred to as a "monster" — and nearly slaying him.

He had a 20-foot birdie putt on the 18th hole to win, but it slid by on the left.

Mediate struggled to keep his emotions after taking bogey on the first extra hole, but he walked off Torrey Pines with 12,000 new friends who crammed both sides of every fairway for a playoff that was tighter than anyone imagined.

"Obviously, I would have loved to win," he said. "I don't know what else to say. They wanted a show, they got one."

Did they ever.

From the opening tee shot Thursday in a light fog known as "June Gloom," this U.S. Open simply shined.

"This is probably the greatest tournament I've ever had," Woods said.

It was filled with some of his greatest moments — a 30 on the back nine Friday to get into the mix, two eagles from a combined 100 feet and a chip-in birdie on Saturday to take the lead, and one of the biggest putts of his career when he holed a 12-foot birdie with the final stroke of regulation to force the playoff.

Then came a playoff in which he built a three-shot lead with eight holes to play, only to find himself trailing four holes later.

Next up for Woods? Even he isn't sure after hobbling around on a knee that clearly hasn't healed.

"I'm going to shut it down for a while," Woods said. He answered "maybe" when asked if he thought he made it worse by playing the Open, and he said he didn't know if he would play the British Open at Royal Birkdale next month.

He nearly shut down too early. Woods seized control when Mediate bogeyed consecutive holes around the turn, but Woods bogeyed the next two from the bunker and Mediate tied him by nearly driving the 267-yard 14th hole and chipping to a foot for birdie. Then the playoff took yet another surprising turn on the 15th.

Woods hit his tee shot so far to the right that it landed in a fairway bunker along the adjoining ninth fairway. But he carved a sand shot around the trees to 12 feet, one of those defining shots that turns a tournament in his favor.

But that didn't happen.

Mediate dropped in a 25-foot birdie putt, while Woods missed and spent the next three holes in a desperate chase to make up ground. Woods finally caught him on the last hole, reaching the green in two and two-putting from 45 feet.

"I never quit. I never quit," Mediate said. "I've been beaten down a few times and came back, and I got what I wanted. I got a chance to beat the best player in the world. And I came up just a touch short."

Woods moved within four of the record 18 professional majors that Nicklaus won. And it was the second time he has won a PGA Tour event and a U.S. Open on the same course — Pebble Beach (2000) and Torrey Pines.

He won the Buick Invitational by a tournament-record eight shots in January, but that was before he had surgery to clean out cartilage in his left knee, before he wasn't sure if pain would shoot down his leg with every swing.

Perhaps the most remarkable aspect of this victory? Woods had four three-putts and four double bogeys, and he still won.

It was his 65th career victory, passing Ben Hogan for third all-time, raised his playoff record to 15-2 and made it 14-of-14 in majors when he had at least a share of the lead going into the final round.

He now has won every major in a playoff except for the British Open.

Just like the last U.S. Open playoff seven years ago, both players arrived wearing the same outfit — khaki trousers and a white shirt at Southern Hills, black slacks and a red shirt with a black vest at Torrey Pines.

That's typical for Woods, and when he saw Mediate, Woods removed his vest.

It felt like a prize fight the way both players marched through a wall of fans and onto the first tee, posing before the silver U.S. Open trophy. And it finished that way, too.

"With everybody in the world all looking in, and everyone expecting me to get my (behind) handed to me, and I didn't," Mediate said. "And I almost got it done. I almost got it done."

Woods raised his arms like a heavyweight champion walking off the first tee, but only because he found the fairway for the first time all week. Mediate flipped his club to the front of the tee box when he came within inches of an ace on the par-3 third.

Back and forth they went, Woods building an early lead with consecutive birdies, Mediate refusing to go away. But when Mediate three-putted from 15 feet for bogey on the ninth, and Woods holed a 20-foot par putt from the fringe on the next hole to go three shots ahead, it looked as though this playoff would turn into another snoozer.

Then it was Woods who faltered, and Mediate caught a second wind. It set up a fabulous finish, just like everything else this week on the public course in the tony hamlet of La Jolla that translates to "The Jewel."

"It was just unreal," Woods said. "It was back and forth, back and forth. And 90 holes wasn't enough."