San Antonio, TX (SportsNetwork.com) - Jimmy Walker fired a 5-under 67 on Friday to move one stroke clear of the field at the Texas Open.

Walker ended 36 holes at 6-under-par 138. Walker, who finished third at this event in 2010, claimed his fourth PGA Tour win earlier this year at the Sony Open in Hawaii.

Charley Hoffman, who led after a windy first round, managed an even-par 72 in round two. He was joined in second place at minus-5 by Aaron Baddeley (71).

Texas native Jordan Spieth carded a 3-under 69 to improve into a share of fourth place at 4-under-par 140. He stands alongside Kevin Na (68).

Former Masters champions Phil Mickelson (72) and Zach Johnson (71) headline a group of five players tied for sixth place at minus-2. They were joined there by Brendan Steele (68), reigning FedExCup champion Billy Horschel (70) and Chris Kirk (71).

The wind was not nearly as strong in Friday's second round on the AT&T Oaks Course at TPC San Antonio. Those that played early Thursday and late Friday got the worst of the wind and David Lingmerth was the low player on the leaderboard from the group. Lingmerth carded a 71 on Friday to end two rounds at 1-over 145.

Walker played the back nine first on Friday and opened with 22-foot birdie putt on the 10th to move to minus-2. After three pars in a row, he got up and down for birdie from a greenside bunker at the par-5 14th.

At the short par-4 17th, Walker drove into a greenside bunker and blasted to 58 feet. However, he 3-putted for bogey to dip to 2-under.

Walker erased that mistake with a 2-putt birdie at the par-5 18th. He started the front side with five pars in a row.

The Texan caught fire starting with a 10-foot birdie putt at the sixth. Walker rolled in a 19-footer for birdie on No. 7 and made it three in a row with a birdie at the eighth. Walker closed with a par to lead by one.

"I was just trying to stay patient. I was hitting some good shots, and made some good par putts, I gave myself some good looks at par there in the first couple of holes on the front nine. Hit some good shots and a made a couple coming in, so that was nice," Walker said. "It was a lot colder this morning, and the course is just going to get tougher."

Baddeley parred his first five holes before making a mess of the 15th. After walking off with a double-bogey, he came back with short birdie putts at 17 and 18 en route to making the turn at minus-4.

The Australian birdied the first and followed with three pars in a row. He knocked in a short birdie putt at the fifth and holed a birdie chance from off the green at six to move to 7-under.

Baddeley missed the green at the par-3 seventh and that led to a bogey. After a par on the eighth, he dropped another stroke on the ninth after a poor drive.

"It was a good day today, A little disappointed with bogeying two of the last three, but I was bit unlucky on seven with a buried ball. Overall, very pleased and looking forward to the weekend," said Baddeley.

Hoffman had back-to-back birdies at 13 and 14, but he dropped a shot at the 15th. Two more birdies on the 17 and 18th helped Hoffman make the turn at minus-8.

However, he stumbled to bogeys at two, five and seven to slide back into a share of second place.

NOTES: Walker owned the 36-hole lead for the fifth time on the PGA Tour ... He converted one of the previous four into victories ... Jim Furyk made the cut on the number and that was his 33rd straight made cut ... Johnson had the lone bogey-free round on Friday ... The cut fell at 6-over-par 150 with 75 players making it to the weekend ... This was the highest cut in event history and was the highest cut outside of the majors since the 2012 Quicken Loans National ... Among those that missed the cut were Justin Leonard, last year's winner Steven Bowditch, Jason Dufner, Lucas Glover, Sean O'Hair and Geoff Ogilvy.