Rory McIlroy's hopes of a second major title suffered a huge setback in Atlanta - but it appeared to have nothing to do with his injured right arm.
Able to play on in the USPGA Championship after suffering a tendon strain hitting a tree root early in his opening 70, the US Open champion had impressively moved only two strokes off third place when trouble struck.
McIlroy, with his arm still bandaged, looked happy enough with his tee shot on the 207-yard 17th - but it came down in the lake short of the green and he then three-putted for a triple-bogey six. From one under par, six behind overnight leader Steve Stricker, he went to two over and joint 55th place.
Stablemate Simon Dyson, however, was up into a tie for fourth place on three under after a birdie on the short seventh and Lee Westwood's birdies at the 12th and 13th to be level par re-ignited his bid.
There were two withdrawals from the event on Friday. Ryder Cup player JB Holmes, who started with an 80, pulled out citing illness and then Rocco Mediate, runner-up to Tiger Woods in the 2008 US Open, did not resume because of injury. His opening round was a 79.
Meanwhile, their compatriot Brandt Snedeker was given a two-stroke penalty for being late for his 8.10am tee time.
Snedeker was 135 seconds late. If it had been five minutes he would have been disqualified, but as it was he went from four over to six over before hitting a shot.