He also matched Spanish legend Seve Ballesteros as the only players in the past century to win their first three majors by at least three shots.
Scheffler squandered a five-stroke edge, Rahm briefly tying him for the lead, but a birdie at the par-five 10th lifted Scheffler back in front to stay.
The 28-year-old Texan took control with birdies at 14 and 15 while Rahm’s closing woes secured the Wanamaker Trophy, his first major win outside of Augusta National.
After suffering a right-hand injury last December, Scheffler only won his first title of the year two weeks ago at the CJ Cup Byron Nelson.
The major victory was Scheffler’s 15th career PGA Tour triumph, all in a span of three years and 94 days, with Jack Nicklaus and Tiger Woods the only players to hit the mark faster.
Scheffler, whose nine titles in 2024 included Paris Olympic gold, converted his eighth consecutive 54-hole lead into a victory.
- With NZ Herald
Live updates of the final round of the PGA Championship at Quail Hollow.