In the first set, both players held their serve and the more experienced Nadal sealed it with winning the tie-break 7-5. There were three breaks in the second set, Nadal breaking his opponent twice and there was never any doubt he would let this lead slip out of his hands.
Nadal has now got a 4-0 winning head-to-head against the Colombian.
The top seed and 2011 Roland Garros champion will meet American Mardy Fish in the semis. Fish triumphed over the Australian Bernard Tomic by beating him 6-7 (5), 6-4, 6-1.