England's Brian Davis lost some momentum at the Travelers Championship in Connecticut on Friday.
The London-born player was in a tie for the lead after the first round but an level-par 70 dropped him back into a share of ninth on six under at the River Highlands course in Cromwell.
Justin Rose also suffered a setback after slipping from his overnight position of joint fifth.
He carded a a two-over-par 72 - which included double-bogeys at the short eighth and par-five 13th - to be six shots adrift of defending champion Hunter Mahan, who shot a seven-under-par 63 to claim the clubhouse lead on nine under.
Kenny Perry is one of six golfers tied for third at seven under after a second-round 67.
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