Sam Burns reeled off four birdies in five holes on the back nine Sunday to win the Sanderson Farms Championship and capture his second career US PGA crown.

The 25-year-old American fired a five-under par 67 in the final round to stand on 22-under 266 after 72 holes at the Country Club of Jackson in Mississippi.

That was good enough for a one-stroke victory over Americans Nick Watney and Cameron Young on the PGA course nearest to Burns' home in neighboring Louisiana.

"It's huge," Burns said of the victory. "I enjoy coming to this place every year, closest I get to playing at home. Such a fun week."

A fourth-place pack on 268 including Sweden's Henrik Norlander and Americans Hayden Buckley, Andrew Landry and Trey Mullinax.

Burns, ranked 25th, won his first US PGA title at the Valspar Championship in May and took his second thanks to solid drives and approaches all week.

"As well as I drove it this week, it set me up for a lot of the second shots," he said.

"The main thing was we knew what our game plan was. We had a purpose for each shot. We tried to stick with our game plan and if we chipped away at it, it would work out for us."

US rookie Sahith Theegala, 23, led by one when the day began and carried that edge after the front nine, but he began the back nine with back-to-back bogeys and fell back while Watney made a charge.

Watney sank back-to-back birdie putts from 25 feet at the par-5 14th and five feet at the par-4 15th to seize the lead on 21-under.

Young sank a 12-foot birdie putt at the par-3 13th to match Watney's lead, Landry joined them with a 14-foot birdie putt at the 16th and Burns sank a 13-foot birdie putt at 13 to equal the co-leaders.

Watney reached the clubhouse on 267 but Landry, Young and Burns were level for the lead and still on the course.

Young fell back with a bogey at 14 and Landry stumbled with a bogey at 17 while Burns made his move.

Burns delivered a tap-in birdie at the par-5 14th to seize the outright lead at 22-under.

Young sank an eight-foot birdie putt at the 15th to move one back.

Burns, however, answered the challenge by dropping his approach at 15 inside three feet of the cup and tapped in for his fourth birdie in five holes to grab a two-stroke advantage.

Burns found a greenside bunker at 18 but blasted out to just inside nine feet and two-putted for bogey to win by a stroke.

World number 657 Watney, 40, missed out on his sixth US PGA title and first since the 2012 Barclays but was thrilled after a closing 65.

"I had a blast," Watney said. "I putted just amazing, one of the best putting rounds I've ever had. The greens are pure. If you get it on line you have a chance."

Young, ranked 173, had missed the cut in all four prior US PGA starts.