Four-time major winner Rory McIlroy made five consecutive birdies in his self-declared best round of the year to share the lead after Thursday’s start of the US PGA Arnold Palmer Invitational.

The 31-year-old from Northern Ireland fired a six-under par 66 at Bay Hill in Orlando to share the lead with Canada’s Corey Conners, one stroke ahead of reigning US Open champion Bryson DeChambeau.

McIlroy, hoping to complete a career Grand Slam at next month’s Masters, opened on the back nine despite weeks of struggling with his swing birdied the second through sixth holes.

“It was good. The 66 is a great way to start the tournament,” McIlroy said. “Hit some really good shots, some good drives.

“I saw a lot of really positive signs out there today, which was really encouraging.”

Conners, another back-nine starter, had four birdies and an eagle in his first seven holes but closed the front and back nines with bogeys, the last from seven feet, to settle for a share of the lead.

“Did a lot of things well. I was off to a great start,” said Conners, who missed the cut in both prior Bay Hill starts but came in rested this time.

“Was ready to go and felt good about my game. I get into ruts when I play too much golf, burn myself out mentally and physically. Been trying to manage my rest.”

McIlroy opened the year with a 64 at Abu Dhabi but said it wasn’t as good as his start at Bay Hill, where he won in 2018 and has top-six showings in his past four starts.

“Pretty much, yeah,” McIlroy said when asked if Thursday was his best round of the year. “With what I’ve been working on over the last few weeks, it has just started to feel a little more comfortable today, which was nice to see.”

McIlroy sank a 13-foot birdie putt at the par-3 14th then holed a 14-footer at the par-3 17th before his lone bogey came at 18.

McIlroy rolled in a birdie putt from 56 feet at the par-3 second to launch his streak, followed with a 22-foot birdie putt and tapped in for birdie at the par-5 fourth after a 40-foot eagle miss.

A great approach left him four feet to birdie the fifth and his run ended with a three-footer at the par-5 sixth after reaching the green in two.

McIlroy plans to borrow from Tiger Woods, an eight-time winner at Bay Hill, as he pushes for his first US PGA triumph since the 2019 WGC HSBC Champions at Shanghai.

“I’ve watched Tiger enough here over the years and the way he played this course was very conservatively,” McIlroy said.

DeChambeau blasted a 351-yard drive at the eighth and had six birdies against a lone bogey.

KUPCHO, KORDA, ERNST SHARE LPGA LEAD: American Jennifer Kupcho fought through a migraine headache to fire a five-under par 67 and share the lead after Thursday’s opening round of the LPGA Drive On Championship.

Kupcho reeled off four birdies in a row on the front nine then hung on through the pain for a bogey-free round to match compatriots Nelly Korda and Austin Ernst for the lead at Golden Ocala near Orlando.

“On 14, I was ready to get off the golf course,” Kupcho said. “Not feeling great.

“On 18 tee, I kind of just started feeling numbness in may hand. I think I have a little bit of stiff neck going on... I stood over it and I was like, ‘There’s no way I can trust myself to hit the shot right now.’”

China’s Yan Jing and American Jaye Marie Green shared fourth on 68 while a pack on 69 included New Zealand’s Lydia Ko, Ireland’s Leona Maguire, Australian Katherine Kirk and American Jessica Korda.