DETROIT -- Matthew Wolff has been working on his mindset, trying to have a good time regardless of results to help him perform closer to his potential.
An ice cream truck outside the Detroit Golf Club seemed to help.
Wolff had a roller-coaster round that went well enough Saturday to give him a three-shot lead in the Rocket Mortgage Classic. He shot his second consecutive 8-under 64 to move into position for his second PGA Tour victory.
"I have to give credit to the ice cream truck that was circling the property," said Wolff, who was 19-under 197 after three rounds. "I'm not joking, actually."
Wolff made a 35-foot putt on the 138-yard No. 5 for birdie, his second of nine birdies.
"I heard the ice cream truck and I'm like, 'I have a good feeling about this,' " Wolff said. "Just had that ice cream truck song in my head. I think that helped me just not think about the speed or the line or anything, just keep my head free."
Ryan Armour and Bryson DeChambeau were tied for second at 16 under after 67s.
Wolff made a 14-foot eagle putt at the 559-yard, par-5 14th to pull into a tie with Armour at 17 under, and added birdies on the par-3 15th and par-5 17th. He finished with the eagle, 9 birdies, 5 pars and 3 bogeys.
If the 21-year-old Wolff can hold on to the lead today, it will be his first victory since the 3M Open last year in Minnesota.
"Just going to go out there, have fun and hopefully I hear the ice cream truck a little bit," he said.
Last year, he made a 26-foot putt from the fringe for eagle on the final hole for a one-stroke win at the 3M Open in his third tournament as a professional. Wolff joined Tiger Woods and Ben Crenshaw as winners of a PGA Tour event and the individual NCAA title -- won at Blessings Golf Club in Northwest Arkansas -- in the same year.
The former Oklahoma State star, though, has struggled enough this season that he was 108th in the world going into the week. He missed the cut at the previous two tournaments and was 54th at the PGA Tour's first event after its restart.
Armour played well and was in a great mood on the front nine while making five birdies to reach 16 under, giving him a one-shot lead.
He chatted and laughed with some fans, watching the tournament from beyond a chain-link fence, near the seventh tee.
The former Ohio State player has his school's logo adorned on the bag, and that caught the attention of some spectators perched on a platform a few minutes later.
"Go get 'em Buckeye," one fan shouted from the backyard of a home.
Otherwise, it was often so quiet sans fans that the jingle from an ice cream truck in the neighborhood and a single-engine plane overhead broke through the eerie silence.
Armour opened the back nine with five consecutive pars before making a birdie at No. 15, helping him keep the lead a little longer before Wolff surged past him.
Armour slipped further behind with a double bogey at No. 17 before bouncing back with a birdie on 18.
"It felt like the front nine was in cruise control. I had looks all the time," he said. "Then the back nine, it got a little squirrelly."
DeChambeau birdied four of the last six holes and pumped his right fist after making a 12-foot birdie putt at 18, pulling him into a tie for second with Armour.
Troy Merritt (67), Mark Hubbard (69), Seamus Power (69) and Chris Kirk (70) were five shots back. Webb Simpson (71) had a bogey on the final hole, falling six strokes behind.
