One-time leader David Howell dropped seven shots in his last seven holes to plummet to a 78 and eight over at halfway in the US Open.
Howell has dropped 12 shots over his last 22 holes at Winged Foot
The 30-year-old Englishman, who let slip a three-shot lead with four to play in his first round, came home in 41 including two double bogeys.
But countryman Luke Donald carded an impressive one-under 69 for seven over.
Other Britons still in contention include Ian Poulter and Darren Clarke (+5) and debutant Philip Archer (+4).
The 34-year-old Archer, who carded his second straight 72, came through a five-man play-off at Walton Heath to claim his spot at Winged Foot.
Spain's Miguel Angel Jimenez also ended on five over, while Dane Thomas Bjorn and Swede Henrik Stenson finished one shot back and will not be ruling themselves out on Sunday.
Howell, however, saw his hopes vanish during a torrid stretch on Winged Foot's front nine.
Starting from the 10th, the European Order of Merit leader bogeyed his first hole and doubled his fourth. But he then steadied the ship with birdies at 15, his sixth, and 2, his ninth.
Then the wheels came off. Sloppy approach play and poor putting saw bogeys come at three, four and six, but worse was still to come as the world number nine double-bogeyed the 7th and 9th.
Howell found 10 of 14 fairways but only eight of 18 greens and took five more putts than the 28 he took on Thursday.
But Howell was not the only European star to be left fuming by Winged Foot's extreme test.
A 72 is by far and away the worst score I could have shot and I managed to do it
Clarke, who added a 72 to his opening 73, described the New York course's greens as "comfortably" the worst he has seen.
The 37-year-old Northern Irishman carded four birdies and six bogeys to be six shots behind clubhouse leader Steve Stricker.
Donald, meanwhile, can also look forward to an upturn in fortunes after recovering from his disastrous opening 78 to card a superb 69 - one of only five rounds under par on Friday.
The talented 28-year-old comfortably made the nine-over cut and is now in a tie for 29th.
But Europeans handed an early exit include Ireland's Paul McGinley (+10), England's Nick Dougherty (+13), Spain's Sergio Garcia (+16) and another English pair Oliver Wilson (+16) and Graeme Storm (+17).