Australian Stuart Appleby fired a three-under-par 69 on Saturday to move two shots clear after the third round of the Houston Open and stay on course for his second PGA Tour win of the season.

Appleby, who began the day with a one stroke lead over England's Greg Owen, mixed five birdies with a pair of bogeys, including one at the last, to reach 14 under for the tournament, giving him a two-stroke cushion over Swede Mathias Gronberg.
   
"I'm looking forward to tomorrow," Appleby told reporters. "I'll be playing one shot at a time and thinking about things that have worked for me this week and I guess what worked for me at the very start of the year and enjoying myself."
   
Winner of the season opening Mercedes Championship, Appleby had a wobble in the middle of his round at the Redstone Golf Club when he bogeyed the eighth and seemed poised to drop another shot on the ninth.
   
But the 34-year-old Australian stopped the slide with a nervy eight-foot par putt and then played error free until the last where he carded only his third bogey of the tournament.
   
"There's a lot of golf, 25 per cent of the tournament still left out there," said Appleby, the 1999 Houston champion. "I never once felt like there was a run away."
   
Gronberg, who needed to return to qualifying school to retain his PGA Tour card this season, returned a five-under 67 to surge into contention at 12-under 204.

After opening with seven pars the Swede struck a rich vein of form by reeling off three consecutive birdies from the eighth and two more from 12 before a bogey-birdie finish.
   
"I had a very slow round going, parred the first seven holes and didn't make a few opportunities where I could have birdied," Gronberg said. "Then I hit a great bunker shot on eight that got my round going."
   
Americans Jerry Smith (69) and Bob Estes, with a six-under 66, are two shots further back at 10-under 206.
   
Owen, who shot a course record seven-under 65 to rocket into contention on Friday, was unable to sustain his form, stumbling to three-over 75 to sit seven shots off the pace.
   
Vijay Singh's hopes of a third consecutive Houston title also faded after a three-over 75 left the Fijian world number three 13 shots behind the leader.
   
The defending champion dropped a shot at the first and struggled through his entire round, mixing bogeys and a double bogey with five birdies for a three-day total of one-under 215.

Padraig Harrington and Graeme McDowell both returned third round 69s to be three under for the tournament.