Rory McIlroy says staying “aggressive” after a fast start was key to taking a one-shot lead in the first round of the US PGA Championship in Oklahoma.
He birdied four in his first six holes en route to a five under 65.
A birdie at the last saw McIlroy finish in style after two late bogeys threatened to stifle his momentum.
“When you get off to a good start sometimes you can start to be cautious or give yourself more room for error, but I stuck to my game plan,” he said.
“I stayed aggressive. I stayed true to what I was trying to do there, which I was happy with.”
Playing alongside Tiger Woods and Jordan Spieth in a hit group at Southern Hills Country Club in Tulsa, McIlroy topped the leaderboard with four straight birdies after opening with a pair of pars from the 10th hole.
Two more birdies saw him take a three-shot lead before bogeys in the sixth and eighth threatened to derail the inning.
“It’s very easy to make bogeys here,” explained the 33-year-old.
“You just get a little bit out of position, you catch a little bit of grain around the green, it’s tricky.
“You’re getting out of position here, just trying to make a par and run to the next one.”
McIlroy is looking for a third US PGA triumph, eight years after his last major win came at the 2014 US PGA at Valhalla.
The victory was a fourth major success for the then 25-year-old, but he hasn’t been able to add to his tally since, with slow starts too often putting him out of contention.
An emotional Sunday at this year’s Masters came too late to pose a real challenge to winner Scottie Scheffler, but served as a reminder of McIlroy’s remarkable quality.
“I played well coming here, in good form,” he said after his round on Thursday.
“Obviously I shot a lot from that round in Augusta, I played well in DC at Wells Fargo and I played well in the practice rounds earlier this week.
“I think when your game feels like that, it’s about going out there and really sticking to your game plan, executing as well as you can and kind of staying in your own little world.
“I did that really well. It was good to get a good start and keep going.”