Adam Schenk leads Jordan Spieth and Tommy Fleetwood at Valspar Championship

The 31-year-old American held a share of the lead overnight and managed to to keep his nose in front on Friday courtesy of a two-under-par 69 at Innisbrook's Copperhead course.

"It really couldn't have been a ton better with the amount of putts I made," said Schenk, who lies on seven-under 135 after 36 holes. "We're doing a really good job managing the courses."

Fellow American Kramer Hickok lies in solo second place a shot further back after a second-round 68, but while both men are chasing their first PGA Tour titles, they can expect some tough competition from some of the players lurking just behind them.

2015 Valspar champion Jordan Spieth lies just two shots off the pace after a 70. He shares third place with fellow Americans Cody Gribble and Davis Riley and England's Tommy Fleetwood.

"Kind of an off day on approaching the greens, hit pretty rusty wedges," Spieth said.

"To shoot one-under on this golf course in the wind is a good score so I feel good about my position going into the weekend."

"I drove the ball maybe the best of the year today. Gave myself a lot of chances with some wedges," Spieth added.

"Couldn't quite get my distance control down on some scoring clubs. But when the wind here is gusty like that and the green depths are so small, it gets really tricky."

After staying in contention with a 69, Fleetwood was looking ahead to a potentially tense weekend with storms forecast for Saturday.

"Patience and having a good attitude will be vital", Fleetwood said. "Just hanging around and seeing what the day gives you."

Another Englishman, Matt Wallace, is part of the group in tied-seventh on four under, three back.