Matt Every's affinity for the Arnold Palmer Invitational was on display again on Thursday as the American fired seven birdies in a seven-under 65 to ease past Rory McIlroy for the first-round lead at Bay Hill in Orlando, Florida.
World No 1 McIlroy was in the clubhouse on 66 when Every - whose two PGA Tour victories came at Bay Hill in 2014 and 2015 - caught fire.
Every's bogey-free round included a 45-foot birdie putt at the par-three second and a 32-foot birdie at the eighth - his penultimate hole of the day.
He found himself atop the leaderboard after missing the cut with a second-round 85 at the Honda Classic last week.
"Sometimes I'm really good, sometimes I'm really bad," Every said. "It's a weird game."
McIlroy was buoyed by an eagle and five birdies in his five-under effort and was one stroke in front of Americans Talor Gooch and Scottie Scheffler.
McIlroy teed off on 10, and was delighted to salvage a bogey at the 11th, where an aggressive second shot found the water and he finished by rolling in an eight-foot putt to limit the damage.
"Making five instead of six there is a big deal," McIlroy said. "One-over through two instead of two-over is sort of a different feeling."
Birdies at 16 and 18 - where he rolled in a 10-footer - had McIlroy heading for the first with "a bit of good pep in my step."
"I played some good golf after that," said McIlroy, who stuck his approach three feet from the pin for a birdie at the first.
He eagled the fourth, where he hit a superb shot out of the fairway bunker to reach the green and made the 24-foot putt.
McIlroy played alongside Olympic gold medallist Justin Rose of England and South Korean Lee Kyoung-Hoon - a late replacement for defending champion Francisco Molinari after the Italian withdrew with a bad back.
It was another disappointment for 2018 British Open champion Molinari, who failed to make the cut in his last three events that featured a halfway cut.
Lee wasn't feeling too hot himself after he and his wife were involved in a car crash on Wednesday morning that left Lee with neck pain.
"I felt sore in the morning, but after I got the tee time I couldn't feel it," quipped Lee, who posted an even par 72.
Brooks Koepka, trying to regain peak form in the wake of a knee injury with the Masters coming up in April, carded an even-par 72.
"Nothing to rave about," said Koepka, who capped his round with back-to-back bogeys at the eighth and ninth. "It's not far off, but it's, still, it's annoying.
"Just can't play golf, can't score," added Koepka, who missed the cut at the Honda Classic last week. His best PGA Tour finish this season is a tie for 43rd at Riviera in February.
Australia's Adam Scott, who won the Genesis Open at Riviera, slumped to a five-over par 77 that included a triple bogey and a double bogey.
Leading first-round scores on Thursday in the US PGA Arnold Palmer Invitational at Bay Hill in Orlando, Florida (USA unless noted, par-72):
65 - Matt Every
66 - Rory McIlroy (NIR)
67 - Talor Gooch, Scottie Scheffler
68 - Sam Burns, Christiaan Bezuidenhout (RSA), Tyrrell Hatton (ENG), Brendon Todd, Keith Mitchell, Graeme McDowell (NIR)
69 - Scott Brown, Kang Sung (KOR), Adam Long, Matt Wallace (ENG), Rob Oppenheim, Harris English, Hideki Matsuyama (JPN), Ian Poulter (ENG)
70 - Emiliano Grillo (ARG), Charley Hoffman, Harold Varner, Zhang Xinjun (CHN), Kevin Na, Collin Morikawa, Tom Hoge, Matthew Fitzpatrick (ENG), Rory Sabbatini (SVK), Im Sung-jae (KOR), Patrick Reed, Matthew NeSmith