Great Britain's Jay Clarke lost to Spain's Alejandro Davidovich Fokina in the first qualifying round of the French Open.
The British number four took the first set and was serving for the match in the second before Davidovich Fokina fought back to win 2-6 7-6 (7-5) 6-1.
The 19-year-old Spaniard faces Portugal's Joao Domingues in the second qualifying round.
Davidovich Fokina is ranked 133rd in the world, 26 places above Clarke.
The 20-year-old Englishman made a fine start as he broke his opponent's serve in both of his first two service games to dominate the opening set.
After fighting back from 4-1 down in the second, Clarke was serving for the match with a 6-5 second-set lead, but the Spaniard broke back and then won the tie-break to take it to a deciding set.
Davidovich Fokina, a winner of the Wimbledon juniors event in 2017, broke immediately in the third set and two further breaks saw him move into the next phase, needing to win two more matches to qualify for the tournament.
Another Briton, James Ward, begins his qualifying campaign against Germany's Oscar Otte later on Monday and hopes to join Kyle Edmund, Cameron Norrie and Dan Evans in the main competition.