The Belgian beat the two-time champion in straight sets on court one earlier today, becoming the first player ever to defeat the Spaniard in the first round of a Grand Slam event.
Speaking after the match, the 29-year-old, who is currently ranked 135th in the world, said: "Rafa did not play his best match here, it is hard when it is your first match on grass.
"I just wanted to play my own game, coming to the net and not playing far from the baseline.
"I have always played well on grass, perhaps not here where I have had some tough draws, but I am really happy. I don't know what to say."
Darcis faces Poland's Lukasz Kubot in the next round.