Garcia-Lopez rallied for a 2-6, 6-4, 6-3 decision over a wild-card Evgeny Donskoy. Garcia-Lopez lost his serve three times in the first set but just once after that. He dropped only four points in five games serving in the third set.
Flavio Cipolla outlasted qualifier Andrei Vasilevski 7-6 (7-4), 7-6 (8-6) by fighting off eight of 11 break points he faced and Rajeev Ram topped Matthias Bachinger 6-4, 6-4 in Monday's other first-round play.
Mikhail Youzhny, who was a finalist in St. Petersburg in 2010 and a semifinalist last year, is the top seed in this year's tournament.
Marin Cilic beat Janko Tipsarevic in the 2011 St. Petersburg Open title match but neither is entered in 2012.