After two rain delays that forced organisers to reschedule some matches to Saturday, Rochus secured his biggest win since he beat then world number two Marat Safin at Wimbledon in 2002.
The Serb committed 62 unforced errors and nearly lost his cool during the two hour, 55 minute second round match.
He slammed his racket during the opening game of the second set when Rochus came back from 0-40 down and after the match he left the court to jeers but still gave the crowd a thumbs up.
Djokovic's loss was the biggest surprise of the day but Spanish fourth seed Rafael Nadal was in no mood to be upset, breezing through his match with a 6-4, 6-3 win over American Taylor Dent.
In the women's draw, world number two Caroline Wozniacki also struggled through her opening match but advanced with a 3-6, 6-3, 6-4 victory over Bulgarian Tsvetana Pironkova.
Justine Henin beat world number five Elena Dementieva 6-3, 6-2 to register her eighth triumph in nine attempts against the Russian, while fellow Belgian Kim Clijsters sped through her 6-1, 6-1 win over Czech Petra Kvitova in just 55 minutes.
Serbian Jelena Jankovic and champion Victoria Azarenka of Belarus also won in the women's draw.
In late matches, Andy Roddick ousted Russian Igor Andreev 6-4, 6-4 in a match that stretched into early Saturday morning, and Frenchman Jo-Wilfried Tsonga beat Spain's Guillermo Garcia-Lopez 6-4, 6-3 to advance in the men's side.
