Tipsarevic, the eighth seed, came through his second consecutive five-set test, defeating Frenchman Julien Benneteau 3-6, 6-4, 2-6, 6-4, 6-3 for a place in the last 16.
Djokovic then exploded when asked about Lance Armstrong and his confession to doping in every one of his seven Tour de France wins.
"He cheated the sport, he cheated many people around the world with his career, with his life story. I think he should suffer for his lies all these years," Djokovic said.
The holder said that he had not been blood tested for half a year, but was still giving urine samples when anti-doping teams came calling.
"Anti-doping regulations a little bit maybe more strict (in tennis) in the sense that you have to fill the whereabouts documents and you have to basically give an hour or two in every day of your life in a whole year, where you are."
"On the other hand, it gives them an opportunity to test you. And you know it is the same for the other players. At least from that point of view, it's fair.
"I have nothing against the anti-doping federation, association, testing me 10, 20, 30 times a year."