Sam Burns secured his third PGA Tour victory in 22 starts, defeating Davis Riley in a playoff at the Valspar Championship on Sunday.

Burns defended his crown against his friend and Junior Ryder Cup teammate, birdieing the second playoff hole with a tough putt from the edge of the green on the notoriously difficult par-four 16th at Copperhead.

"It was crazy. Davis played really well, especially the way he finished," Burns said afterwards. "We didn't make a lot of mistakes, and I think a lot of times on Sundays, if you can plot your way around, make a bunch of pars, throw in a few birdies here and there, a lot of times it works well.

"My coach actually came down on Monday. I struggled in the final round of The Players and I needed some help."

On going up against Riley in the playoff, Burns admittedly won with a tinge of lament.

"It [the playoff] was a blast," Burns said. "Unfortunately, I got the better end of it today but throughout our careers we're going to have a lot of battles. He's a heck of player and I'm happy for how well he's been playing."

Burns and Riley were tied at 17-under-par after 72 holes, after the former bogeyed the penultimate hole, his first for the day.

The world number eight, who made five bogies and a double bogey playing in the last group at The Players Championship at Sawgrass the weekend prior, almost went without a blemish at Copperhead. With the finish line in sight, he hit the bunker on the par-three 17th and couldn't recover.

Riley then had a chance to putt for the tournament on the closing hole, after he birdied the 17th to tie with Burns, and set up a makeable birdie on the par-four 18th.

His putt drifted agonisingly wide of the cup, forcing a playoff. Riley's tee shot on the opening playoff hole faded into the rough before finding the bunker, while Burns made the green in regulation, but both made par.

The defending champion managed to birdie the notorious par-four 16th despite hitting the rough from the tee.