Alcaraz, 21, cruised through the opening two sets 6-3, 6-4, but faced challenges in the third set, getting broken three times by his resilient opponent and losing 6-1.
Ugo Humbert, who is on a seven-match winning streak after winning the Antwerp title last month, missed four match points but battled to a 7-6 (7/4), 6-7 (6/8), 7-6 (7/3) victory
