© Manuel Queimadelos/Mallorca Championships
Mannarino will face second-seeded Austrian Thiem in the second round
The World No. 42 saved all four break points that he faced and won 61 per cent (14/23) of his second-service points to advance at the new ATP 250 grass-court event in Spain.
Struff had beaten Russian Daniil Medvedev at the NOVENTI OPEN in Halle last week on home soil, but could not overcome Mannarino. The 32-year-old will play second-seeded Austrian Dominic Thiem in the second round.
The Australian, who is currently No. 81 in the FedEx ATP Rankings, hit 14 aces and saved a match point at 4-5 in the second set, and he will next face either Dusan Lajovic or qualifier, Lukas Klein in the second round.