Every carded a 7-under par 65 in the first round Thursday at the Bay Hill Club & Lodge in Orlando, Fla. The two-time defending champion sits at No. 309 in the Official World Golf Ranking.
"I just didn't want to shoot myself out of the tournament with the way the weather was," Every told PGATour.com. "The putter was a little shaky. It's always a little shaky. It was a good day for me."
McIlroy -- the No. 1 golfer in the world -- shot a 6-under par 66 in the first round.
Every birdied three of his first four holes. He also made birdie on No. 8 and turned in a 4-under par 32 on the front nine. He birdied three more holes on the back nine to finish 3-under par down the stretch. McIlroy tallied five birdies and an eagle, but carded a bogey on No. 11.
Talor Gooch was 5-under par in the first round and sits in third place. There are eight players tied for fourth place. World No. 3 Brooks Koepka is tied for 45th after carding an even-par 72. No. 9 Patrick Reed fired a 2-under par 70 and is tied for 18th after the first round. No. 10 Tommy Fleetwood struggled with a 3-over par 75 on Thursday at Bay Hill.
Francesco Molinari is the defending champion of the tournament. The Italian golfer withdrew from this year's tournament due to a back injury.
The 2020 Arnold Palmer Invitational ends Sunday.