The field is packed at the 2019 Wells Fargo Championship, but Rory McIlroy and Joel Dahmen stand above the rest after Round 1. 

McIlroy and Dahmen carded a five-under 66 to take a one-stroke lead over the field following Thursday's first round. Adam Schenk, Martin Laird, Patrick Reed, Nick Taylor and Dylan Frittelli are currently tied for third place at four under.

McIlroy did the entirety of his damage on the back nine, making the turn at even par before going on a tear that sent him rocketing up the leaderboard. He had back-to-back birdies on Nos. 10 and 11, highlighted by a brilliant approach out of the rough to within two feet on No. 11, then went for three straight from 14-16.

The best shot of that three-hole stretch was a blast out of the greenside bunker on the 329-yard par-four 14th. After trying to drive the green, McIlroy found himself in the bunker and hit an approach within six feet that he converted for birdie.

Quail Hollow has been one of McIlroy's favorite courses during his PGA career. The Wells Fargo Championship, PGA Championship and Deutsche Bank Championship are the only three events where he's won multiple times. McIlroy's score of 267 is a course record by five strokes, and his seven-stroke victory in 2015 is the largest in the event's history.

The world No. 4, who turns 30 on Saturday, is playing in his first tournament since placing 21st at the Masters. He said the time off helped him fine tune his game. 

"One of the good things about having two weeks off is that you have time to delve into a couple of things," McIlroy told reporters. "There were a few particular shots that I struggled with that week (at the Masters). I just went back and looked at the swings that I made and I noticed a couple of things in my swing that were sort of going off. I had a good few days with my coach Michael Bannon last week and we worked on a few things.

"Aiming so far in either direction that you're playing for a big curve or a big miss has never really been my game. I just sort of delved into that a little, worked on a couple of mechanics and feel a little bit better about it coming into this week."

McIlroy had not finished worse than sixth in an event during the 2019 calendar year before the Masters, so this performance is par for the course. He's been the most consistent golfer in the world this year and should be considered a favorite heading into the PGA.

Dahmen is a 31-year-old who has never won on the PGA Tour. He won twice on the PGA Tour Canada in 2014 but has mostly spent his PGA career fighting for his Tour card. The Washington native showed no signs of fear moving his way up the leaderboard Thursday, shooting a near-flawless round and birdieing No. 18 to tie McIlroy at the top.

Dahmen knocked down three birdies outside 10 feet, missed just one fairway and only three greens in one of the best rounds of his PGA Tour career. 

Elsewhere, world No. 2 Justin Rose is in a tie for 29th after shooting a one-under 70. McIlroy, Rose and Rickie Fowler (E, T-47) are the only top-10 players in the field.

Among the notables closer to the lead are Jason Day (-3), Sergio Garcia (-2) and Webb Simpson (-2).