ST. LOUIS: Brooks Koepka held off dramatic challenges from Tiger Woods and Adam Scott in a thrilling back-nine battle Sunday to win the 100th PGA Championship.

The 28-year-old two-time US Open champion sealed his third major title by firing a four-under-par 66 to finish 72 holes on 16-under 264 and defeat Woods by two strokes at Bellerive Country Club with Australia’s Scott another shot adrift.

As Woods electrified spectators by displaying the form that made him a 14-time major champion, American rival Koepka stayed calm and persevered under intense pressure.

Deadlocked for the lead with Scott and only one stroke ahead of Woods, Koepka sank a 10-foot birdie putt at the par-4 15th and a six-foot birdie putt at the par-3 16th then parred the last two holes to secure the victory.

Woods, who hasn’t won a major title since the 2008 US Open and hasn’t won any title in five years, proved he is a legitimate major title contender once again at age 42 with an epic 64 he ended with a 20-foot birdie putt at 18.