Jordan Spieth won his second PGA Tour title after claiming the Valspar Championship in a play-off with Patrick Reed and Sean O'Hair.

The 21-year-old's first tour success came in the 2013 John Deere classic, also on play-off, and he kept his nerve on the third extra hole to put some wind in his sails heading into Masters season.

Spieth was just two under for the day at Florida's Innisbrook Resort, compared to Reed's five-under 66 and O'Hair's four-under 67, but after all three made successive pars in the play-off he made the decisive birdie at the par-three 17th.

Reed had taken the clubhouse lead late in the day when he holed a dramatic birdie putt from 31 feet, with raucous celebrations to follow, but Spieth and O'Hair joined him on 10-under for the tournament to force the three-way shootout.

Overnight leader Ryan Moore saw his challenge dissipate with a messy round of one over that included six bogies, eventually finishing in fifth behind the highest-placed European, Henrik Stenson.

Harris English pocketed five birdies on the back nine for a day's best 65 but had to make do with a seven-way tie for 10th.