Rochus defeated the former champion 6-2, 6-7 (7-9), 6-4 on Friday, Mar 26 in the second round of the tournament.
Djokovic's error-filled performance led to his shock exit. He double faulted ten times and committed 62 unforced errors.
"I never expected to win," said Rochus after the match.
"Novak, he has won a Masters Series five times; he won a grand slam, many things I have never did in my life. He is number two, so I think he has more experience than me," he added.