California - Rory McIlroy lamented a "frustrating" putting performance in the Frys.com Open second round in northern California on Friday while Brendan Steele increased his lead to two shots despite shooting seven strokes worse than his opening round.
A 25-foot birdie at the first hole was an ideal start for Steele, who shot an opening 63, but he failed to fire for the rest of the round and finished with a two-under-par 70 at the Silverado Resort in the opening event of the PGA Tour season.
Steele posted an 11-under halfway total to head a group of four that includes Jhonattan Vegas, who stumbled with a bogey at the par-five 18th after taking four strokes from 60 yards.
The Venezuelan (71) slipped back to nine-under with Canadian Graham DeLaet (68) and Americans Will Wilcox (67) and Harold Varner (70).
Englishman Justin Rose (69) was among a group three strokes behind, while McIlroy was six shots off the pace after shooting a 71 that included just two birdies.
McIlroy collected both of his birdies with mid-range putts but frittered away a few golden opportunities, including putts of three and five feet.
McIlroy said he had yet to find his touch on the greens since returning from an ankle injury at the PGA Championship in August.
"Very frustrating," said the four-times major champion. "It's been like this since I came back. I need to figure it out a little bit. I just need to see some putts going in the hole.
"I think it's more mental than anything else. Whenever you don't see anything go in, it makes it harder and harder each and every hole that goes by.
"So hopefully (I) find something on the putting green tonight and then if I can get off to a good start in terms of holing putts tomorrow, hopefully that can feed through ... and I can go from there."
Leader Steele, whose lone victory came at the 2011 Texas Open, is coming off a solid season in which he posted a runner-up finish at his home event, the Humana Classic, a tie for 12th at the PGA Championship and finished 50th in the FedEx Cup standings.
133 - Brendan Steele 63-70
135 - Will Wilcox 68-67, Jhonattan Vegas (VEN) 64-71, Graham DeLaet (CAN) 67-68, Harold Varner 65-70
136 - Martin Laird (SCO) 65-71, Justin Rose (ENG) 67-69, Russell Henley 67-69, Justin Thomas 66-70
137 - Colt Knost 71-66, Patrick Rodgers 68-69, J.J. Henry 68-69, Tyrone Van Aswegen (RSA) 69-68
138 - Jonas Blixt (SWE) 70-68, Charles Howell 69-69, Chris Stroud 69-69, Michael Kim 71-67, Boo Weekley 69-69