The four players closest to him overnight all dropped shots. Woody Austin’s closing bogey left him two behind, Zach Johnson bogeyed the 17th and 18th to be three back, Masters champion Phil Mickelson bogeyed the last to be fourth on seven under and Australian Adam Scott’s double-bogey six on the 17th left him with five strokes to make up.

Britain’s David Howell, meanwhile, completed a nightmare 83 and fell right away from joint-ninth at halfway to 62nd spot.

A week after reaching the world top 10 for the first time with his runaway victory in the BMW Championship at Wentworth, Howell double-bogeyed three of the first four holes and went to the turn in 45.

In stark contrast to that Justin Rose, who went to bed on Friday night thinking he had been disqualified from the event, was in a tie for 13th with Paul Casey.

Rose and his playing partner Ryan Moore left the course on Friday night five minutes before play was officially suspended because of bad light and were told they were out of the $5.7m (€4.4m) tournament as a result.

Feeling hard done by because the information to stop was given to them by their official scorer, the pair were given the chance to state their case at first light on Saturday morning and were reinstated.

Rose birdied three of his last four holes in the second round to survive the cut with two shots to spare, then followed up with a 67 to improve a further 44 places.

“It was a tough decision, but I think it was the right call,” Rose said.

While he was delighted to end the day three under Casey was disappointed. He had climbed into a tie for sixth, but finished with two bogeys.

Pettersson missed out on a place in the US Open last Monday when the latest world rankings showed him at 51st rather than 50th by 0.01pts, but a second US Tour victory – he captured the Chrysler Championship last October – would save him the need to qualify tomorrow.

It would also lift him from 24th to eighth on the Ryder Cup world points list.