Top seed Kei Nishikori got the defence of his Barcelona Open title off to a winning start, beating Teymuraz Gabashvili 6-3 6-4 on Tuesday.
The world number five took 69 minutes to see off his Russian opponent - a break in each set enough to seal his progression to the third round.
There were also second-round wins for Spanish duo Roberto Bautista Agut and Tommy Robredo, who saw off Thomaz Bellucci (6-3 6-4) and Mikhail Kukushkin (6-3 6-2) respectively.
Robredo's win represented a 250th victory for the 2004 champion on clay.
Pablo Cuevas triumphed 6-4 7-5 over Roberto Carballes Baena in the day's remaining second-round tie, with the rest of the action taking place in the first round - Nicolas Almagro booking a clash with second seed Rafael Nadal in the next stage.
The world number 123 was 3-0 up in the first set when opponent Paolo Lorenzi was forced to retire.
Albert Montanes defeated Ricardas Berankis 1-6 6-4 7-5 to set up a meeting with David Ferrer, while fourth seed Marin Cilic will face Victor Estrella Burgos after the Dominican beat Dominic Thiem 6-3 7-6 (7-3).
Qualifier and world number 329 Andrey Rublev, meanwhile, registered the biggest win of his career by ousting 2010 winner Fernando Verdasco 7-6 (7-4) 6-3.
Elsewhere, Joao Sousa, Marsel Ilhan and Juan Monaco made it through with wins against Kenny de Schepper, James Ward and Alejandro Gonzalez respectively.