The world No 1 marched on in his quest to capture the Paris title, the only Grand Slam he is yet to claim, and will face Australian teenager??Thanasi Kokkinakis next time out.
His 24th consecutive victory was aided by a remarkable 35 winners yet Djokovic will still be grateful for his third round berth after seemingly hurting his groin.
At 5-4 in the second set he required a medical time-out that was more concerning that anything Muller was able to muster, although it was shaken off long before the victory was wrapped up.
Djokovic said: “The groin is nothing major. It wasn’t pleasant as the conditions changed. The court was slippy and I jammed my hip a little bit.
“Thankfully it’s nothing major. So it’s not a concern for the next match. I made a couple of slides that were quite unusual ??with changes of direction.”
His upcoming opponent Kokkanakis, who beat Bernard Tomic in the second round, said: “Novak barely misses a ball, he’s mentally tough, lightning quick on court. The list goes on.
“He just does everything so well and so professionally. I guess that’s why he’s had such great success.”