Sixth seed Federico Delbonis got the better of Gilles Simon in their first-round clash at the Grand Prix Hassan II in Casablanca.
Simon would have been the third seed in the tournament but his entry came so late that he had to go through qualifying.
He successfully negotiated that hurdle but fell 6-4 6-4 to Argentinian Delbonis, who next meets another qualifier in Filip Peliwo.
The 20-year-old Canadian won just his second ATP Tour match with a first-round victory over Italian Filippo Volandri.
Spain's Roberto Carballes Baena won the battle of the qualifiers against David Goffin but there were first-round exits for local wild cards Hicham Khaddari and Lamine Ouahab.
Ouahab in particular put up a good fight, losing out 6-3 2-6 6-1 to Spaniard Albert Ramos, while Khaddari was beaten 7-6 (7/3) 6-3 by Romania's Victor Hanescu.
Hanescu next plays top seed Kevin Anderson, who had a first-round bye.