Defending champion Hideki Matsuyama was pleasantly surprised to find himself sharing the first-round lead of the Memorial, while the surprises for five-time winner Tiger Woods were less welcome.

Matsuyama on Thursday had eight birdies without a blemish on his card to share the first-round lead in the Jack Nicklaus-hosted US PGA Tour event with American Bo Van Pelt on eight-under par 64.

Van Pelt had 10 birdies and a clutch par save from a bunker at 18 for his slice of the lead.

They had a two-shot lead over Scotland's Russell Knox and Jason Dufner, who shared third on 66, with another seven players tied on 67.

Masters champion Jordan Spieth headed a group of nine on 68 that also included major winners Justin Rose of England and Keegan Bradley.

But Woods, the 14-time major champion who has plunged to 172nd in the world rankings, wasn't in the mix after scrambling to a 73.

Only a late-round rally saw the former world number one -- seeking his first victory since August of 2013 -- salvage a one-over round after he played his first nine holes in four-over -- with four bogeys and a double-bogey along with two birdies.

"I didn't play very good today at all. I didn't have much with my game," said Woods, who battled back with three birdies on his second nine. "But I fought hard, I fought hard to get back. And to get it back on a golf course like that, it was pretty good work."

While Woods struggled with a two-way miss, Matsuyama was delighted to find himself playing better than his practice had led him to expect.

"To be honest with you, up until yesterday I was not hitting the ball very well, I was not chipping very well, I was not putting very well," said Matsuyama, who is trying to join Woods as players to successfully defend a Memorial title. "And I don't know what happened overnight. We just caught magic."

Matsuyama's eight birdies included four in a row at the 11th, 12th, 13th and 14th.

For Van Pelt, who grew up just across the state line in Indiana, leading the Memorial was a dream.

It wasn't as easy as 10 birdies might have made it look, however.

"This course is never easy, but I had good speed with the putter," he said. "Making (birdies at) all four par-fives helped. I think three of them I was on the green in two. The other one I was just off.

"Anytime you can do that, it's a big help," he added.

Former US PGA Championship winner Jason Dufner was tied for the lead heading to 18 but found water off the tee and finished with a bogey.

Jason Dufner was at eight-under heading to the 18th but found water off the tee. That led to a double-bogey that dropped him into the tie for second with Knox, who bogeyed his final hole, the ninth.
Source: AFP