Playing just the second major of his career, American Collin Morikawa won the US PGA Championship in sensational fashion after a thrilling final round in San Francisco.

Morikawa emerged from a seven-way tie for the lead in the closing stages at Harding Park by chipping in for a birdie on the 14th hole and then producing a stunning eagle on the 16th, driving the green on the 294-yard par four and holing from seven feet.

The 23-year-old carded a closing 64 – equalling the lowest round of the week – to finish 13 under par and two shots ahead of overnight leader Dustin Johnson and England’s Paul Casey, who barely put a foot wrong in pursuit of his first major title at the 64th attempt.

Casey carded five birdies and a solitary bogey in a final round of 66 to record his best finish in a major, with Matthew Wolff, Jason Day, Bryson DeChambeau, Tony Finau and Scottie Scheffler all sharing fourth place on 10 under.

“I played wonderful golf. Collin thoroughly deserves it,” Casey said. “I mean, what a shot he hit on 16, just awesome golf. There’s nothing you can do except tip your cap to that.

“I’m very, very happy. It’s been a great week, a strange week obviously missing the fans.”

Morikawa, who beat Justin Thomas in a play-off in the Workday Charity Open last month for his second PGA Tour title, began the day two shots off the lead and had to hole lengthy par putts on the first two holes.

Birdies on the third, fourth and 10th took Morikawa into a tie for the lead which became a six and then seven-way tie until his moments of brilliance on the 14th and 16th proved decisive.

Defending champion Brooks Koepka, who was chasing an historic hat-trick of victories in the event, began the day on the same score as Morikawa but slumped to a closing 74.