SAN DIEGO (California) (AFP) - Tiger Woods drained a birdie putt at the final hole Sunday to set up a David vs Goliath 18-hole playoff with unheralded American Rocco Mediate at the 108th US Open golf championship. Woods completed a two-over 73 to force the Monday showdown with Mediate, who fired an even-par 71 on the Torrey Pines South course for a one-under total of 283. "The green wasn't very smooth," Woods said. "I kept telling myself make a pure stroke. If it bounces in or out, so be it, at least I can hold my head up high and hit a pure stroke. I hit it exactly where I wanted to, and it went in." Mediate was watching from a scoring booth as Woods's putt curled around the lip of the cup before dropping. Mediate, a 45-year-old who has won five times on the US PGA Tour but is seeking his first major title, said he was certain it would go in. "Unbelievable, I knew he would make it," Mediate said. "How much better can this get?" England's Lee Westwood had a chance to join the playoff with a birdie at the last, but his 20 footer trickled away from the cup and left him with a 73 for even-par 284. Woods started the day with a one-shot lead over Westwood, with Mediate a further shot back. The world No.1 owns a perfect 13-0 record in major championships in which he has held or shared the lead going into the final round, but he couldn't get any momentum going as he posted his worst score of the week. But he'll get a chance to take his total of major triumphs to 14 on Monday as he continues his pursuit of Jack Nicklaus's record of 18. Woods, still showing some signs of pain in his surgically repaired left knee, was leading Mediate by one shot through 12 holes before a bogey at the par-five 13th, a hole he had eagled in the past two rounds. Woods was on the left edge of the fairway off the tee, and hit his second shot left into the hazard. Westwood bogeyed 13 in similar fashion, while at the same time Mediate birdied 14 from a greenside bunker to seize the advantage. Westwood, who had seen his nine-hole lead evaporate when he bogeyed three of the first four holes after the turn, also birdied 14 to stay in the chase, but his last birdie of the day proved to be too little, even after Woods and Mediate both bogeyed 15. "It's sickening not to be in the playoff," Westwood said. "I could have played my way out of it completely after 10, 12, 13, but a lot of strange things happen the last few holes of major championships, as they did today. Made a good birdie at 14, and just failed to make birdie at the last. It's a bit disappointing." Mediate missed a 10-footer for birdie at 17, and two-putted from 35 feet at 18. "I was trying to beat him on my putt, my 35-footer," said Mediate, who tapped in for par. "I just didn't quite get it out there. But anyway, I made good putts on 16 and 17 just to be here." Two of Woods's major triumphs have come in playoffs. He won the 2000 US PGA Championship with a three-hole playoff victory over Bob May, and he downed Chris DiMarco at the first hole of sudden death to win the 2005 Masters. Monday will mark his first experience of the US Open 18-hole playoff, which will start at 9:00am (16:00 GMT). "After I got the start off today it looked like I could play myself right out of the tournament. But I still have a chance tomorrow." Woods dropped three shots in his first two holes with a double-bogey at the first and bogey at the second. Mediate vaulted into the early lead with a birdie at the second, but said he knew all day that Woods could pounce at any time. "Whatever he did on the first couple of holes, you never say he's done," said Mediate, who nonetheless toured the course with the same lighthearted demeanor he displayed in the earlier rounds. "You never count this man out." Woods pulled off his birdie at 18 despite hitting his tee shot into a fairway bunker and his second shot into the rough. On the tee, Woods said, he was thinking "Just put the ball in the fairway. I didn't do that. I laid up in the fairway to at least have a good number, I didn't do that."At least I gave myself a putt at it, and I happened to hole it." Sweden's Robert Karlsson and American D.J. Trahan shared fourth place on two-over 286, Karlsson posting an even-par 71 and Trahan a 72. Geoff Ogilvy, the 2006 US Open champion, and two-time winner Ernie Els of South Africa hovered on the leaderboard briefly, but back-to-back bogeys at 16 and 17 saw Ogilvy finish tied for ninth at four-over and Els finished tied for 14th at five-over.