Cameron Norrie fell to an early exit at the Monte Carlo Masters as he lost to Francisco Cerundolo in the first round.
The British number one, ranked 13th in the world, was beaten 6-3 6-4 by Argentina's Cerundolo on the Mediterranean clay.
Norrie, 27, looked unsettled throughout the match and made 18 unforced errors compared with only eight winners.
Cerundolo, 24, gained the decisive break in the ninth game of the second set when Norrie netted a forehand.
Norrie started the season with a run of 21 wins from 25 matches but also lost his opening match at the Miami Open last month when he was defeated by France's Gregoire Barrere.