Britain's Tommy Fleetwood birdied four of the last six holes, including two spectacular birdie putts from beyond 40 feet, to grab a one-stroke lead after Saturday's third round of the US PGA Honda Classic.

The 29-year-old Englishman, runner-up at the 2018 US Open and 2019 British Open, fired a three-under-par 67 to finish on five-under 205 after 54 holes at PGA National in Palm Beach Gardens, Florida.

Fleetwood, who began the day three strokes off the lead, made six birdies against three bogeys on a wild day where he was the only player to shoot a round under par in the final eight groups.

"It's funny, really, how tough certain shots can play," Fleetwood said. 

"There are just so many factors on a golf course. You can only hit golf shots and see where they play."

American Brendan Steele, the 36-hole leader who was three ahead of Fleetwood when the day began, fired a 71 to stand second on 206 with England's 46-year-old Lee Westwood and 42-year-old Luke Donald both on 207 after 71s Saturday.

"I didn't have my A-game today," said Westwood, seeking his first US PGA win since 2010. 

"Struggled with my game a little bit. Stayed patient and ground it out. I don't think I did too much damage."

Fleetwood dropped the ball within six feet at the par-three sixth and made the birdie putt, then suffered a three-putt bogey from 85 feet at the par-three seventh. He answered with a five-foot birdie at the ninth but needed four shots to find the 10th green and took a bogey.

His closing charge began with a "lovey putt" for birdie from 14 feet at 13, followed by a monster 45-footer for birdie at 14.

"Just looking to lag that one up close. Wasn't expecting it to go in," Fleetwood said. "Bit of a bonus there."

After finding sand with his first two shots at the par-three 15th, Fleetwood blasted out and sank a testy 10-foot bogey putt.

"The putt at 15 for bogey was big," Fleetwood said.

It bolstered his confidence heading to the finish and at the par-3 17th he rolled in a 48-foot birdie putt.

"At 17, again, another bonus one in there, just to walk it in," Fleetwood said.

On the par-five 18th, Fleetwood became only the day's seventh player to reach the green in two, then rolled a 44-foot eagle putt to two feet and tapped in for birdie.