Giraldo started the match with a lot of confidence, but from 2-2 and 30-0 in his favour, it was Nadal who stepped up and managed to win the next 10 games to book his place in the third round.
Nadal will play the Czech Radek Stepanek next, who beat Tommy Haas of Germany 7-6 (4) 6-1.
Into the third round is also the 7th seed Tomas Berdych, who defeated the Frenchman Nicolas Mahut 7-5 6-1.
Berdych will face Grigor Dimitrov of Bulgaria next. Dimitrov overcame the Argentine Juan Ignacio Chela in three sets 6-2 4-6 6-4.