Star draws Matt Fitzpatrick and Henrik Stenson were upstaged on day three of the Scandinavian Invitation as Erik Van Rooyen claimed the 54-hole lead in Gothenburg.
Fitzpatrick slept on a two-shot lead ahead of Stenson overnight, but the final pairing both struggled to keep errors off their cards as they fired one-under 69s, while Van Rooyen roared into the lead with five birdies over the last six holes to cap a 64.
Van Rooyen, still chasing his maiden European Tour win after two runner-up finishes and three other top-10s this season, was one over for the day after a mixed start before birdies at the sixth and eighth got his challenge back on track.
The South African put together a steady run of pars around the turn before producing an outstanding finish, with three consecutive birdies from the 13th followed by back-to-back gains at 17 and 18 which lifted him to the top of the leaderboard on 13-under par.
Fitzpatrick got to 13 under when he rolled in his third birdie putt of the day at the 12th, but the Englishman then bogeyed 14 and ran up a double-bogey six at the 16th when he thinned his drive and his ball hit a tree and dropped into a hazard.
He was in trouble off the tee again at the long 18th as he tugged his drive into a fairway bunker, but he drilled his second into the fringe to the right of the green and holed the monster putt for a closing eagle which hauled him back to within one of the leader.
Fitzpatrick shares second with Australian Wade Ormsby, who carded five birdies on the back nine in a 65, while Ashun Wu's 67 was blighted only by a late mistake at the 14th which would ultimately cost him a tie for the lead with Van Rooyen.
The huge galleries following home favourite Stenson were disappointed on the very first hole as he opened with a double-bogey six and, after a birdie at the third, he erred again at the sixth and remained two over for the day at the turn.
But Stenson revived his hopes with morale-boosting birdies at 10 and 11, and he got under the card with another gain at the 14th before parring home to stay at 10 under along with 2014 Ryder Cup winner Jamie Donaldson, Dean Burmester, Alex Levy and Gavin Moynihan
Burmester enjoyed the low round of the day, carding an eagle and six birdies in a superb 62 which propelled him 27 places up the leaderboard, while Donaldson birdied five of the last seven holes to return a 63 - five years to the day since the last of his three European Tour victories.
The ever-popular Andrew "Beef" Johnston also fired 63 which he completed with four consecutive birdies as he gave himself an outside chance of victory, although he will start the final round with six strokes to make up on Van Rooyen.