Stuart Appleby carded a final round five-under 67 to storm to a record-equalling six-shot victory at the Houston Open last night.

Appleby, who also won of the season-opening Mercedes championship, began the day with a two-stroke lead over Sweden's Mathias Gronberg and steadily built on his advantage as he cruised to a winning score of 19-under 269.

It was the 34-year-old Australian's eighth career PGA Tour win and his second in Houston to go along with his 1999 victory.

Appleby joined Tiger Woods and Phil Mickelson as the only players with more than one PGA Tour wins this season.

"Certainly now winning twice puts that feeling, an emotional feeling at a high level, to say that I won twice," Appleby, who has never won more than one title in a single year, told reporters. "It's a good year. Winning twice on the Tour in a year is a good achievement for me.

"Other players are probably thinking four or five and other guys are thinking if they don't win six it's a bad year.  I think inning once or twice proves to you that what you're doing works, and it can work more than once every Blue Moon."

Perched alone atop the leaderboard all week, Appleby began his final round by picking up a shot at the first and never stepped off the gas, mixing seven birdies with a pair of bogeys.

American Bob Estes finished with a 69 to take second with 13-under 275, and Steve Stricker fired a day's best six-under 66 to finish one shot further adrift.

Gronberg, who had stayed in touch with Appleby through the first nine, stumbled on the home stretch by dropping shots at 13, 16 and 17 to finish with a one-over 73, alone in fourth on 277.

Fijian Vijay Singh's bid for a third consecutive Houston title ended with a one-under 71.

The world number three failed to mount a charge on the final day, mixing three birdies with a pair of bogeys for a total of two-under 286.

Padraig Harrington finished well down the field on four under while Graeme McDowell carded a final round of 75 to drop to level par for the tournament.