Spaniard Lopez got off to the best possible start when he claimed an early break of serve. He pressed home that advantage to claim the opening set 6-3.
Darcis responded positively in the second set though and forced a decider when he won by the same scoreline that he had just been defeated by.
Both players traded service games up until the point of 5-5 in the deciding set.
It was Lopez who claimed the decisive break of serve to take a 6-5 lead, before he served out to book his place in the next round.