British number one Kyle Edmund was beaten by Italian qualifier Andreas Seppi in the first round of the Monte Carlo Masters in Monaco.
Edmund, who reached his maiden ATP Tour final on Sunday, was beaten 6-3 5-7 6-2 by the world number 62.
The Briton struggled on a slow surface, converting just two of his 11 break points as he lost in two hours three minutes.
Seppi will play Spain's Guillermo Garcia-Lopez in the second round.
Both players saved break points in their opening service games before Seppi won four consecutive games to put Edmund under pressure.