A year of major heartache ended with Jason Day breaking through in a major way Sunday at the PGA Championship.

With at least a share of the 54-hole lead for the third straight major, Day never gave Jordan Spieth or anyone else much of a chance at Whistling Straits. He closed with a 5-under 67 for a three-shot victory and broke Tiger Woods' major championship record for most strokes under par by finishing at 20 under.

In tears before tapping in for par, Day hugged his son and wife and then Spieth, who earned a small consolation prize with his runner-up finish. Spieth moved to No. 1 in the world, ending the one-year reign of Rory McIlroy.

"I didn't expect I was going to cry," Day said. "A lot of emotion has come out because I've been so close so many times and fallen short. To be able to play the way I did today, especially with Jordan in my group, I could tell that he was the favorite. Just to be able to finish the way I did was amazing."

What a journey for the 27-year Australian.

He understood hard times as a youth when his father died of cancer when Day was 12. For all his talent, he was questioned for winning only one tournament in five years on the PGA Tour. With a share of the lead at the U.S. Open and British Open, he had to watch someone else celebrate.

Not on this day. Not even close.

Day started the final round with a two-shot lead and no one got any closer than that the entire day. His lone shaky moment came at the end of the front nine, when he made his first bogey on No. 8 and then chunked a wedge from the fairway on No. 9. But he saved par with an 8-foot putt and was on his way.

And he knew it at the end.

With a three-shot lead on the par-5 16th, Day hit a high draw onto the green, bit his lower lip and swatted longtime coach and caddie Colin Swatton in the arm. That two-putt birdie took him to 20 under, and two pars sealed the victory.

Woods finished at 19 under when he won the 2000 British Open at St. Andrews.

Spieth was chasing history again. Woods and Ben Hogan are the only two players to win three majors in the same season, but the Masters and U.S. Open champion had a tougher time chasing Day.

The 22-year-old Texan missed a pair of birdie putts early on the back nine, and he struggled with his driver on the front nine. But he's not sure it would have mattered. Day wasn't going to let this chance get a way, and everyone knew it.

"It was Jason's day," he said. "He played like he'd won seven or eight majors. He took it back. He wailed on it. It was a stripe show."

Spieth set a record of his own. By closing with a 68, he set a record by playing the four majors in 54-under par, breaking by one the mark that Woods set in 2000. The difference is that Woods won two majors by a combined 23 shots.

That also speaks to the depth of golf in this generation, and Day is the latest example. He moved to No. 3 in the world, meaning the top four in the world are all under 27 and have combined to win five of the last six majors.

It starts with Spieth, the second-youngest player behind Woods to reach No. 1. Spieth got there in his 77th start as a pro. Woods was 21 when he became No. 1 for the first time in just his 21st tournament.

"It's an unbelievable feeling," Spieth said. "So much work has been put in. What a year it's been."

Branden Grace of South Africa had another mistake on the back nine in a major that cost him. Grace was tied for the lead at the U.S. Open when he hit his tee shot on the railroad tracks and out-of-bounds at Chambers Bay. This time, he was two shots behind when he went long of the 10th green and made double bogey. He closed with a 69 and finished third, five shots behind.

Justin Rose got within two shots until making a double bogey for the third straight day. He closed with a 70 and finished fourth.

Day faced enormous pressure of having a lead for the first time going into the final round, trying to avoid becoming the first player since the PGA Championship went to stroke play in 1958 to have at least a share of the 54-hole lead in three straight majors without winning.

It sure didn't show.

"There wasn't a whole lot I could have done today," Spieth said.

Day won for the third time this year on the PGA Tour, one behind Spieth, and sixth time in his career.

McIlroy made a solid return from an ankle injury that kept him out since the U.S. Open. He had a 68-69 weekend and finished 17th, though it wasn't enough to stay No. 1

"Honestly, the way Jordan has been playing and the way I haven't played much this year ... if he does go to No. 1 today, it's very deservedly so," McIlroy said. "I know the golf you have to play to get to that spot, and it has been impressive this year."