Wyndham Clark leads AP Invitational, SA's Christiaan Bezuidenhout in the mix

The World No 7 and reigning US Open champion carded a five-under 67 at Bay Hill, mastering gusty winds that challenged the field.

Clark, who finished runner-up to Scottie Scheffler in last year's event, pulled ahead with an 18-foot birdie putt on the par-five 16th, then capped his round with a superb approach on the 18th, setting up a tap-in birdie.

"It's nice to put some good numbers on this golf course and if anything it's really good momentum for the rest of the week," Clark said.

Clark leads a tightly packed chase group of four players at three under: South Africa's Christiaan Bezuidenhout, Keegan Bradley, Corey Conners, and Shane Lowry, who all signed for rounds of 69.

Lowry's playing partner, Northern Ireland's Rory McIlroy, sits in a tie for sixth at two under after an up-and-down round of 70.

McIlroy's scorecard featured six birdies but was marred by four bogeys, including a dropped shot on the par-four 18th.

Despite the mixed performance, the four-time major champion was satisfied with his opening round.

"I think the guys that teed off a little later got a little bit of a reprieve," McIlroy said.

"It was still breezy, but not quite as tough as the guys got it this morning. Yeah, couple under was a good start."

Defending champion Scheffler sits just one shot behind McIlroy at one under, part of a strong group that also features Collin Morikawa, Justin Thomas, and Patrick Cantlay.