Scott Hend took a one-shot lead into the back nine as the final round of the Omega European Masters was set up for a dramatic finish at Crans-sur-Sierre Golf Club.
The Australian entered round four with a three-shot lead after completing five holes of the third round in the morning and turned in 34 to get to 13 under.
England's Matthew Fitzpatrick has two top tens in three appearances in the mountains and he played his first ten holes in four under to sit a shot off the lead, one ahead of Paraguay's Fabrizio Zanotti.
China's Ashun Wu and South African Darren Fichardt were then at nine under.
Fitzpatrick and Hend finished second here in 2015 and 2016 respectively, while Zanotti is looking for a second European Tour title of the season after winning the Maybank Championship.
Hend dropped a shot after finding sand off the tee on the par three third and when he hit a poor tee-shot on the next to surrender another bogey, the lead was down to one and the door was open for the charging Wu.
The 32 year old made birdies on the fifth, sixth and seventh and when he finished inches from an ace on the par three eighth, he was tied at the top at ten under par.
That did not last long, however, as Hend got a fortunate break after sending his tee-shot left into the trees on the fifth. The ball fell nicely and Hend hit a brilliant hooked second to set up a ten-foot birdie.
Zanotti also birdied the fifth in more conventional style, hitting his approach to similar range and joining Wu at ten under.
Fitzpatrick had birdied the second thanks to a smart approach and while he bogeyed the fifth after sending his second shot over the back of the green, he bounced back with a birdie on the sixth after a good chip-and-run
The three-time winner then played another nice chip to set up another birdie on the seventh and an excellent tee-shot on the eighth meant he was in a share of the lead.
Hend missed the green on the drivable seventh but played an impressive chip of his own to get back to level par for the day and into the lead.
Fitzpatrick had a golden opportunity to join him and make it four in a row after a wonderful pitch into the ninth but he missed his birdie putt from eight feet.
The 23 year old made up for it on the next, hitting a beautiful approach in and rolling his birdie putt up the hill.
Zanotti played the ninth in textbook fashion to get within a shot of the lead but not for long as Hend, who had powered his way to the side of the green in two, got up and down to also make a birdie.
Wu had dropped a shot on the ninth to drop to nine under after 12 holes, with Fichardt recovering from bogeys on the third and sixth with birdies on the eighth, ninth and tenth playing alongside Fitzpatrick.
Defending champion Alex Noren, fellow Swede Alexander Björk, Australian Marcus Fraser and England's Tyrrell Hatton were then at eight under.