World number 110 Yang, with just one previous win in the United States to his name, landed his second in style, first overturning a two-shot lead and then eagling the par-four 14th hole to move in front before holding his nerve down the stretch to seal victory at seven under par with a two-under round of 70.

Woods came up short by three shots, taking a 75 for second place, with Lee Westwood and Rory McIlroy tied for third place at three under.

The catalyst for Yang's victory came when he sent down a brilliant bunker shot for eagle at the par-four 14th as Woods birdied to take a one-shot lead with four to play.

Woods had begun the fourth round at a rain-softened Hazeltine with a two-shot lead at eight under par over playing partner Yang and defending champion Padraig Harrington of Ireland.

Yang upped the ante with a birdie at the par-five third and Woods folded at the par-three fourth, three-putting for bogey to fall into a tie with the Korean at seven under.

Yang’s time in the lead was short-lived as he bogeyed the fifth, while Harrington narrowly missed birdie chances at the fifth and sixth to stay tied for second at six under.

A third of an inch of rain had fallen overnight on the 7,674-yard, par-72 Minnesota course after Woods completed a third-round 71 to move closer to a record-tying fifth US PGA title.

Playing conservative, low-risk golf, the world number one had seen his four-stroke halfway lead cut in half by Yang’s five-under 67 and Harrington’s 69.

Also within reach of Woods, winner of his last two tournaments, was Glover and Sweden’s Henrik Stenson, a further two shots in arrears at four under par, with Denmark’s Soren Kjeldsen and Ernie Els of South Africa at three under.

Padraig Harrington had duelled with Woods the previous Sunday at the WGC-Bridgestone Invitational until playing a disastrous 16th hole in Akron, Ohio, and the Dubliner’s reign as PGA champion was undone in one hole seven days later with a calamity at the par-three eighth, a quintuple bogey eight having found the right-sided lake off the tee.

Woods took bogey at the same hole to fall to six under and the co-leaders made the turn with a three-shot lead over the field.

The US PGA champion had come out of the final pairing for the last 13 years and Woods took control once more with a birdie at the par-five 11th, only to bogey the 12th and drop back into a share of the lead with the Korean at six under.

Then came Yang’s moment of magic at the 14th, Woods making birdie to stay in the hunt with four to play. There was still time for drama as Woods bogeyed the par-three 17th only for Yang to miss his par putt and the Korean went to the 72nd hole still with a one-shot lead over the world number one.

Yang stayed cool at the 18th and sent in a remarkable hybrid shot from the left fairway fringe under a tree that just missed the hole, the Korean allowing himself a fist pump. From the other side but on the fairway, Woods’ five iron found left greenside rough.

That left Woods needing yet another miracle shot to rescue but his effort ran past the hole and Yang had two putts from 10 feet to become US PGA champion. He needed just one and history was made, Woods bogeying the 18th for his 75.

Westwood, third at last month’s Open having bogeyed the 72nd hole to miss a play-off with Stewart Cink and Tom Watson, birdied the par-four 14th en route to a two-under 70 to be first in the clubhouse at three under.

“I played very well today, very solidly as I have done all week,” Westwood said.

“I made a few too many mistakes on the greens, but I’m sure everybody can say that.

“It was a good bounce-back after a bit of a disappointment at the Open, not winning there.”

Rory McIlroy was next to join him having rebounded from a double-bogey six at the first, completing a round of 70 with five birdies and one bogey, the 20-year-old securing a second top-10 finish in a major this year having tied for 10th at the US Open.

Glover had got to six under after five holes before being derailed by four bogeys in the next seven holes. A birdie at the 15th restored him to three under but he bogeyed the last for a 74 to take fifth place at two under.

South Africa’s Ernie Els (74), Stenson (75), Germany’s Martin Kaymer (73) and Denmark’s Soren Kjeldsen (74) tied for sixth place at two under par, while Harrington closed with a 78 to tie for 10th with Americans Dustin Johnson (70), Zach Johnson (71) and John Merrick (70) as well as Northern Irishman Graeme McDowell (72) and Italy’s Francesco Molinari (72), making it eight Europeans in the final top 10.