Giraldo, from Risaralda, needed only seventeen minutes to win the first set 6-2.
But the Brazilian gained strength in the second set, in which his long passes left the home player without a chance.
The third set brought a decision though. After changing shirts, Giraldo appeared to have found new motivation and the Colombian eventually secured a 6-4 result, winning the match 2-1 in sets.
Another two Colombians have a chance of making it to the quarter finals: Carlos Salamanca faces Argentinian Diego Hartfield and Michael Quintero meets with Canadian Frederic Niemeyer as they battle for a place among the best eight.