World No 1 Rory McIlroy staged a second-round charge, flirting with the course record before taking a bogey at his last for a seven-under 63 to sit two off the pace at the Charles Schwab Challenge in Texas.
Until the final hole the Co Down ace had been working on an erro- free round highlighted by a 23-foot putt for eagle at the par five first.
Birdies at two, six and seven put McIlroy at eight-under and one off the tournament record with two to play but his chances of 61 ended with a bogey as he joined Xander Schauffele (66) and Colin Morikawa (67) in the clubhouse at nine-under.
Harold Varner III opened with a triple bogey and closed with a flurry of five birdies over his last six holes to surge into the early second-round lead.
Playing the back nine first at the spectatorless Colonial Country Club, Varner got his day off to a horrific start with a triple at the par four 10th but hit back with birdies at 12, 13 and 16 to return to level par.
He wobbled into the turn with a bogey at 18 but then jumped to the top of the leaderboard behind a run of four straight birdies from the fourth and another at his last for a four-under 66 and get to 11-under for the tournament.
Lurking one shot back is local favourite Jordan Spieth, who had his own troubles mid-round before recovering for a five-under 65.
