Danny Willett of England, the Masters champion on both sides of the Atlantic, shot a 5-under 65 to be one stroke off the lead after the European Masters first round on Thursday.
Willett began the defense of his title in the scenic Swiss Alps among nine players trailing joint leaders Paul Peterson of the United States, Frenchmen Gregory Havret and Mike Lorenzo-Vera, and Daniel Brooks of England.
Peterson, a lefty who won the Czech Masters two weeks ago, had four birdies in a five-hole section from 14 to 18 in his round of 64.
The group on 5 under included Andrew "Beef" Johnston of England.
Among Europe's Ryder Cup team, Lee Westwood shot a 2-over 72 and Matt Fitzpatrick had a 5-over 75. Captain Darren Clarke carded a 78.