Rory McIlroy has surrendered his BMW PGA Championship defence after a second-round 78 saw him finish well adrift of the cut line at Wentworth.
The world number one reached the turn on Friday level-par for the tournament, but a bogey at 10 triggered a run of dropped shots which left him on five-over-par.
Only last week, the Northern Irishman broke his own course record at Quail Hollow on his way to victory at the Wells Fargo Championship, but that form deserted him at the European Tour's flagship event.
Francesco Molinari made birdies at the final two holes to retain his overnight lead, although it was cut to one by An Byeong-Hun, who surpassed the Italian's opening-day 65 by going round in eight-under-par.
Emiliano Grillo and Thongchai Jaidee are also in the chasing pack at eight-under, with James Morrison the highest-placed Englishman at seven-under and European veterans Miguel Angel Jimenez and Robert Karlsson a shot further back.