Johnson Wagner led throughout to win his first PGA Tour victory at the Shell Houston Open.

Wagner shot a final-round 71 to finish at 16 under and defeat Chad Campbell and Geoff Ogilvy by two strokes last night.

Billy Mayfair - in his 600th Tour event - and Fred Couples finished tied for fourth, the latter achieving his highest finish since a tie for third at the 2006 Masters.

Wagner received an automatic invitation to this week's Masters.

"I can't believe I'm playing Augusta," he said. "It's a dream come true."

Wagner began the final day with a one-stroke lead and extended it to three when he made a 27-foot birdie putt - and Campbell missed a five-footer to save par on number two.

The lead grew to five strokes as Wagner continued to fare well and Campbell endured a disastrous front nine.

Wagner's lead dwindled on the back nine but he held off the challenge as the pack closed - and Campbell recovered his composure.