Ryan Evans shot a 6-under 66 to take the first round lead at the Czech Masters on Thursday.
The 29-year-old Englishman, who is seeking his first European Tour title, birdied the 18th to finish one stroke ahead of defending champion Thomas Pieters of Belgium and Peter Hanson of Sweden.
Coming off a fourth-place finish at the Olympic course in Rio de Janeiro on Sunday, Pieters opened with four birdies on the back nine and surged to a 7 under after two straight birdies on the fifth and sixth holes. But he fell back after a double bogey on the eighth.
Hanson produced a flawless round with five birdies.
Lee Westwood, who hopes to be a wildcard pick for the European Ryder Cup team, shot 70.