Hunter Mahan shot a 1-under 71 on Sunday to win the US PGA Tour’s Houston Open, edging out Carl Pettersson by one stroke.

Mahan, who won the Match Play Championship in February, is the first two-time champion on the PGA Tour this year.

The victory moved Mahan up to No.4 in the world rankings, the first time he’s ever been the highest-ranked American.

Pettersson (71) finished with eight pars for his second runner-up finish this year.

Third-round leader Louis Oosthuizen (75) was another shot back at 14 under.

John Senden carded a final-round 74 to finish the best placed Australian at tied 18th, while Marc Leishman (72) was a further shot back.

Mahan began the day two shots behind Oosthuizen, who lost the lead with two double bogeys on his front nine.

The 29-year-old Mahan earned his fifth career victory. He has six top-25 finishes in seven starts this year.