Three-way tie for Rocket Classic lead as SA's Potgieter stays in the hunt

Potgieter soared into a share of the lead on the opening day at Detroit Golf Club with a new course-record 62 but could only manage a two-under 70 on Friday. That took the big-hitting 20-year-old's total from 10 under to 12 under, leaving him two shots off the lead.

A trio of Americans took over at the top on Friday - Philip Knowles made three eagles in a remarkable round of 64 to grab a share of the lead with Chris Kirk and Andrew Putnam, who had rounds of 65 and 66 respectively.

"I got pretty lucky a couple times," said Knowles, who is ranked just 519th in the world. "I hit quality shots that ended up going in the hole, but I can't imagine chipping in three times for eagle ever again in my life."

Knowles is playing on a medical exemption after a string of injuries over the last two years, while he has only made two cuts in 11 prior starts this season.

"It has not been my best year thus far by any stretch of the imagination, but golf is funny," he said. "When you're playing bad, you never feel like you're going to play good again, and when you have days like today, you just don't understand how you could ever shoot a bad round of golf.

"So it was super rewarding."

Putnam carded a bogey-free 66, starting strong with birdies on three of the first four holes. He then holed an 88-foot chip from the fairway for eagle at the par-five seventh and later saved par with an up-and-down from the bunker on 14.

"It didn't feel like bogey free," Putnam said. "It felt like I was kind of all over the place on the back nine, but the front nine was pretty simple golf. Wind came up, got a couple tricky holes out there, so glad I could grind it out."

Kirk shot a 65, opening with three straight birdies and finishing with back-to-back birdies. He’s chasing his seventh career PGA Tour title and his first since last year’s Tournament of Champions in Hawaii.

"Dream start for sure," Kirk said. "Then was able to add a few more. Back nine was a little bit more hit and miss... But I was in a really good rhythm. Proud of the way I hung in there and kept hitting good shots."

American Jackson Suber was in solo fourth a shot further back, followed by Potgieter, who shares fifth with Mark Hubbard and Michael Thorbjornsen.