Phil Mickelson now holds the longest run of major starts, with 55. Mickelson shot a second straight 71 on Sunday and finished at 6 under in his final tuneup before Augusta.
"It was a good week for me to identify what I need to work on and find out what areas don't feel great," Mickelson said. "My chipping and putting aren't where they need to be. Fortunately, I can spend extra time on it now, the next couple of days leading into the Masters."
This day belonged to Wagner, the 13th player to earn his first victory in Houston.
He started one ahead of Campbell, then opened a three-shot lead when he sank a 26-foot birdie on the second hole and Campbell three-putted. Wagner led by five after a birdie on the fourth. Campbell hit into the fairway bunker off the tee and bogeyed again.
Campbell drove into the fairway bunker on No. 8, then dumped his second shot into the water, leading to a crippling double bogey. Wagner birdied again to get to 17 under.
Ogilvy birdied Nos. 3, 5 and 8 to move into second place, but Wagner led by four at the turn.
Couples, the 2003 champion when the tournament was played at the members' course across the street, was one of several players who mounted charges on the back nine.
Wagner bogeyed the 10th and Couples and Mayfair both birdied 13 and 15, the last two par 5s, to move to 13 under, tying Ogilvy. Campbell bounced back with three straight birdies on 11, 12 and 13 to get to 14 under. Estes also birdied the 11th and 12th to reach 14 under.
But Wagner hung on, as the players chasing him stalled, one after another.
Wagner left a long birdie putt short on the par-4 17th, but he calmly sank the 11-footer to stay at 16 under. He drove his last tee shot into the fairway bunker, avoiding the ominous pond that runs down the left side of the 18th hole.
"It's not where I wanted to hit it," he said. "It was the safe alternative to the big lake on the left."
Wagner became the second wire-to-wire winner since the tournament moved to the Tournament Course at Redstone in 2006. Stuart Appleby led from the start when he won in 2006.
Divots: Appleby, last year's runner-up, shot a pair of 70s on the weekend and finished at 6 under. ... Pat Perez shot a 64, the low round of the day and his best round of the year, to finish at 10 under. ... Wagner, born in Amarillo, is the seventh Texan to win the Houston Open.
