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.