Mickelson found himself in the second group out at 8:25am following a third round of 78, a stark contrast to his Open Championship triumph at Muirfield last month.
The World No 2 looked in danger of finishing last of the 75 players who made the cut when he went to the turn in 39 with two birdies, one bogey, one double bogey and a triple bogey, but a back nine of 33 ensured he finished one shot better than compatriot Gary Woodland.
Low scoring remained possible on a course where only 10 players had finished under par in the previous five majors staged here, with Germany’s Martin Kaymer carding birdies at the first, third and fourth.
However, the Ryder Cup hero also showed what dangers were lurking for the leaders when he ran up a triple-bogey seven on the fifth — as had Mickelson — by chipping from just off the green into the water.
Former US Open champion Jim Furyk held a one-shot lead over Jason Dufner on nine under par, with Sweden’s Henrik Stenson seven under and his compatriot Jonas Blixt another shot back.
Masters champion Adam Scott and veteran American Steve Stricker were four off the lead with defending champion Rory McIlroy and Lee Westwood six off the pace on three under.
Meanwhile, South African Tim Clark had recorded the first hole-in-one of the week, holing from 220 yards on the 11th with a 3-hybrid. — PA Sport