Top-seed Kei Nishikori began the defence of his Barcelona Open title with a 6-3, 6-4 victory over Teymuraz Gabashvili of Russia.
Nishikori hit 22 winners and held his serve to win the second-round match on the outdoor clay court in one hour, eight minutes.
The fifth-ranked Japanese player could face last year's runner-up Santiago Giraldo on Thursday if the Colombian gets past Joao Sousa.
Nicolas Almagro also advanced to the second round, where he will face eight-time winner Rafael Nadal, after opponent Paolo Lorenzi retired 10 minutes into the match with Almagro leading 3-0.
Last year, Almagro stunned Nadal in the quarter-finals, ending Nadal's run of 41 straight wins at the tournament.
"It was a great first match,'' Nishikori said. "It was my first match of the year on clay, so I was little tight, but I played a great two sets today.''
Earlier, Russian teenager Andrey Rublev beat 2010 champion Fernando Verdasco 7-6, 6-3 in the first round. The 17-year-old Rublev, who entered as a qualifier ranked 329th, broke the Spaniard three times while saving five break chances.