Long-hitting Bubba Watson fired a five-under-par 67, the lowest round of the day, to grab a share of the lead at the halfway stage of the $5.5 million Houston Open.
Watson, tied for the lead with five others including holder Stuart Appleby, sank putts of 35 and 20 feet on his way to six birdies against a solitary bogey for a two-round total of six-under-par 138.
Appleby, who shot 66 on Thursday to share the first-round lead, shot an even-par 72 to join a leading group that also included Americans Jason Gore (68), Jeff Maggert (71), Bob Estes (71) and D.J. Brigman (68).
Americans Tommy Armour III (71), Hunter Mahan (71) and Tom Byrum (68) were knotted one stroke adrift at five-under 139 with six more players a further shot behind.
Ireland's Padraig Harrington shot a level par 72 and is five shots off the lead. The Dubliner had another uninspiring day mixing three birdies with three bogeys in his 72 for a one-under-par total of 143.
The 7,457-yard course at Redstone Golf Club, set up to mimic Augusta National, the venue for next week's US Masters, played to the strength of Watson, who said he is still learning how to manage his power game.
"Trust it that I can hit a wedge pretty close, and I've done that a couple times this week where I went ahead and laid up and tried to play smart," he said. "I'm trying to just learn the game that way, play my percentages."
Watson said he still lacks course management skills.
"I feel like my game is starting to come around and my mental game is starting to get better," he added. "Now it's probably 25 percent instead of 10 percent."
Gore, an unlikely contender at the 2005 US Open at Pinehurst before an ugly final-round 84, credited his putter for a 68, two shots better than his opening round.
"That's kind of the way golf goes," said Gore, who played with Retief Goosen in the final group at Pinehurst and ended up 14 shots behind winner Michael Campbell of New Zealand.
"I hit it inside 10 feet a bunch yesterday and didn't make anything and didn't hit it so good and made a lot of putts today. It's a crazy game."
Grouped at 140 were world number five Adam Scott of Australia, South Korean K.J. Choi, Daniel Chopra of Sweden, South African Tim Clark and Americans Justin Leonard and Paul Stankowski.
Seventy-eight players made the cut set at one-over 145.
Among those missing out were Spaniards Jose Maria Olazabal (146) and Miguel Angel Jimenez (146), Sweden's Jesper Parnevik (151) and New Zealander Campbell (155).
