American Jason Kokrak secured his second PGA Tour win of the season after a two-shot victory in the Charles Schwab Challenge in Texas.

Jordan Spieth, who had led by a shot going into the final round, bogeyed the 18th to finish second on 12 under par.

England’s Ian Poulter finished in a four-way tie for third, two shots further back, with a final round of 68.

Kokrak, 35, broke his PGA Tour duck when he won last October’s CJ Cup on his 233rd career start.

Spieth had a nightmare start to his final round with three bogeys in his opening four holes, while Kokrak was almost as shaky with two dropped shots over the first four.

But he took a one-shot lead at the sixth with the second of two birdies, and then regained it at the eighth before Spieth drew level at the turn.

Kokrak edged in front again with another birdie at the 11th and never let the lead slip after that, with Spieth finding the water at the 18th with his approach shot.