Fabio Fognini in Stuttgart semis
Fognini saved the only break point he faced and converted two of his six chances to beat the seventh-seeded Giraldo in 81 minutes.
The top-seeded Italian, who is bidding to reach his fourth final of the season, next faces the third-seeded Roberto Bautista Agut, who beat Spanish compatriot and No. 6 Guillermo Garcia-Lopez 3-6, 6-4, 7-6 (1).
Lukas Rosol upset the fourth-seeded Feliciano Lopez of Spain 4-6, 6-3, 7-6 (4). The 48th-ranked Czech next faces second-seeded Russian Mikhail Youzhny. The 2002 tournament winner defeated Argentina's eighth-seeded Federico Delbonis 7-6 (2), 6-2.
Youzhny won 74 percent of his service points and saved the three break points he faced for victory in 1 hour, 41 minutes.
Copyright 2014 by The Associated Press