South African Louis Oosthuizen came under pressure from two of Europe's finest as the British Open continued in more windy conditions at St Andrews.
Forced to wait 28 hours between the end of his second round and the start of his third - Friday's suspension of play was part of the reason for that - Oosthuizen had not even driven off when his lead came down to four.
Swede Henrik Stenson was responsible for that, charging through the field from 28th to second with an outward 32 and kissing his ball when he holed his sand wedge approach to the 465-yard 13th for an eagle two.
Stenson, with nothing better than an eighth place all season and struggling to retain his Ryder Cup place, did then bogey the 16th and 17th, but a closing birdie gave him a 67 and made him the early clubhouse leader on seven under.
By then, however, England's Paul Casey had cut Oosthuizen's advantage to two with birdies at the second, third and long fifth - and that became only one when he picked up his fourth shot at the 371-yard seventh to improve to 10 under.
The overnight leader, meanwhile, had three-putted the opening green and could 'only' par the next five.
As for 50-year-old 1989 champion Mark Calcavecchia, he suffered calamity after calamity over the initial stretch of holes.
He also three-putted the first and after bogeys on the next two as well he crashed to a quadruple bogey nine at the 568-yard fifth - a hole which had seen five eagles during the day, but also a bogey six from Tiger Woods as he strived to stay in the hunt for a third successive Open title at the Home of Golf.
Casey had much the better of his head-to-head with compatriot Lee Westwood, who slipped back alongside Woods on four under with bogeys at the fourth and sixth.
With Oosthuizen failing to tighten his grip there were any number of players still with ambitions of the Claret Jug.
Korean Jin Jeong, the reigning British amateur champion, was among those to eagle the fifth and with it he joined Stenson on seven under.
Spaniard Alejandro Canizares was on the same mark and only one further back stood Stenson's fellow countryman Robert Karlsson, South African Retief Goosen and American Ricky Barnes.
Stenson's day actually stared at 4.15am. He and 29 others first had to finish his second round and after parring the 17th he birdied the last for a 74 and two under aggregate.
"I went back for some sleep in a couple of patches, then came back," he said.
"Obviously it was a good day for me. I made a bomb of 60-70 feet on the eight and at the 13th hit my five-wood about 320 yards and then a sand wedge."
"I couldn't see where it landed, but the crowd went crazy and I figured that was a good sign."
"It's tough conditions out there and we will see where I stand, but I have some experience that might come in handy tomorrow."
He finished joint third at Birkdale two years ago.
Rory McIlroy - 63 on Thursday, 80 on Friday - was not totally out of it after a 69 lifted him back to four under.
But Ian Poulter, runner-up in 2008, fell away to four over with a 76 and then had more trouble off the course.
Making his way back to the players' lounge a spectator made a comment which he refused to repeat, but said was 'personal and inappropriate', and then he had an exchange of words with a steward.
Casey drove to the green on the 352-yard ninth and with two putts for his fifth birdie turned in a sparkling 31 for the second day running.
Oosthuizen, though, birdied the seventh and another two holes later re-established a two-stroke lead at 13 under.
The pair had moved clear of the field, with Stenson, Kaymer and Canizares next best at seven under.