Rory McIlroy admitted he was tempted to exercise caution after surprisingly finding himself in the hunt for a third US PGA title at Oak Hill.
Although McIlroy continued to struggle off the tee, he scored 69 points in the second round and equaled par midway, putting him just five points behind the lead shared by Scottie Scheffler, Corey Conners and Viktor Hovland.
First-round leader Bryson DeChambeau and fellow American Justin Suh were two shots from the lead, while England’s Callum Tarren – who only secured a place in the field on Friday after former champion Martin Kaymer retired – hit another shot after an excellent 67.
Masters runner-up Brooks Koepka was next to Tarren at two unders thanks to a 66 that included four birdies in the last seven holes.
Justin Rose hit just two fairways but somehow managed to hit a second round of 70 where he was one down, with McIlroy and former Open champion Shane Lowry level.
Lowry had started with six birdies within eight holes before giving up on his 67th hole on the 17th and 18th.
McIlroy was among the later starters, taking advantage of unexpectedly calm conditions and a course softened by several rain showers to complete his final ten holes three-under par.
“I have to be patient on the tee shot,” McIlroy said. “I stayed very patient and I think it was rewarded with a couple of breaks and birdies towards the end.
“I think considering how awful I felt about the ball because I’m only five behind… I’m not suggesting it could be up there with one of my best performances, but when I got that (birdie-) putt on the last hole I thought, I can’t believe I’m only five behind.
“If I can get the ball in play from the tee then I’ve got a shot and at that point I could just tee it off high and bomb it anywhere. I might as well just hit hard and go.”
World No. 1 Jon Rahm hit 68 to set the halftime average at four over par, but playing partner and US Open champion Matt Fitzpatrick missed the last two holes and missed the game by one shot.
Club pro Michael Block had previously insisted he could fight for an exceptional win after leveling the scores with McIlroy and Lowry for a second straight season.
Block, one of 20 PGA pros in the field in Rochester and head pro at Arroyo Trabuco Golf Club in California, made the cut for the first time in seven majors but had set much higher goals.
“I’m having a great time,” said the 46-year-old Block after a round of four birdies, two bogeys and a double bogey on the fifth that was the result of a dreaded shot off the tee.
“I have no pressure, I have a job and a paycheck waiting for me at my club. I don’t have to make putts to pay my mortgage. That’s a nice thing I have here.
“To tell the truth, I feel like I have the game this week to measure myself. I feel like I could get steady shots out here any day. I have a feeling that at the end of the four days that could be a pretty good result.”
Block has the words “Why not?” embossed on the balls, reminding him not to doubt his abilities when the pressure is on, which stems from him potting a putt to qualify for the US Open to qualify in 2007.
And asked what the ultimate “why not?” was. he added: “Win by far. As strange as it may sound, I’m going to enter a competition. I promise you that.”