Second seed Albert Ramos-Vinolas came from a set down to claim his place in the quarter-finals of the Grand Prix Hassan II at the expense of Laslo Djere on Wednesday.
The 24th-ranked Spaniard, beaten by Pablo Cuevas in the Brasil Open final last month, battled past the Serbian qualifier to win 6-7 (4-7) 6-1 6-4 in Marrakech.
Ramos-Vinolas needed almost two and a half hours to make it through to the last eight, securing the only break of the deciding set to knock the world number 184 out.
Borna Coric was also made to work for his quarter-final spot as he was taken all the way by Reda El Amrani, but came through 6-2 3-6 7-6 (7-5).
Last year's runner-up Coric was in trouble at 4-2 down in the final set, but El Amrani was denied victory after being pegged back at 5-5 and losing the tie-break.
Fifth seed Paolo Lorenzi and Benoit Paire, seeded six, are through to the second round following wins over Guillermo Garcia-Lopez and Carlos Berlocq respectively.
There were also first-round victories for Jiri Vesely and Jeremy Chardy.