Fabrizio Zanotti turned in 31 to open up a one-shot lead early on day one of the Omega European Masters.
The consistent Paraguayan won his second European Tour title earlier this season at the Maybank Championship and a scoring burst in the middle of his first nine holes handed him an excellent start in the hunt for number three at Crans-sur-Sierre Golf Club.
Last week's winner Haydn Porteous and England's Tyrrell Hatton were then at three under, with a group of 12 players a further shot back.
The mountain setting of Crans Montana provides one of the most dramatic backdrops of the entire season and there was scoring to match the setting early on the tricky layout.
Zanotti started with three pars from the tenth but birdied the 13th, made an eagle on the par five next and followed it with another gain on the 15th.
South African Porteous arrived in Switzerland full of confidence after his victory at the D+D REAL Czech Masters and he birdied the 14th before eagling the 15th, with the back-to-back par fives providing scoring opportunities in his first eight holes.
Hatton also had an eagle in his first six holes but in less conventional fashion, holing his second on the par four 12th before adding a gain on the 15th.
Former champion Miguel Angel Jiménez, Scott Hend - who lost in a play-off here last season - former World Number One Luke Donald and Ryder Cup star Matthew Fitzpatrick were then all in the group at two under.