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.
Woods, who delivered so many spectacular moments over four days along the Pacific bluffs, only needed a two-putt par at the end 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 off 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 it held up for 91 holes, and the payoff was worth the pain.
Woods joins Jack Nicklaus as the only players to capture the career Grand Slam three times over.