The world number three will now play either South Korea's Hyeon Chung or Italy's Marco Cecchinato in the next round of the Association of Tennis Professionals World Tour Masters 1000 competition. 

"Both of these players won against me, the last time we met," said Djokovic, the 14-time Grand Slam champion.

"I think I'm a completely different player than I was in the first, five, six months of the year. 

"Hopefully the outcome can be different, as well.

"I'm very grateful to play on a high level. 

"I think that I'm very close to my best, you know, and my best changes day to day.

"I can always strive to be the best I can be on that given day. 

"Today's performance was pretty close to that."

Djokovic has won three Shanghai Masters previously, in 2012, 2013 and 2015.

In other matches, Nicolas Jarry of Chile surprised Croatia's Marin Čilić when he beat him 2-6, 7-6, 7-5 to also secure his place in the final 16.

Borna Ćorić of Croatia has progressed after beating America's Bradley Klahn 6-4, 6-2, while Australia's Matthew Ebden was victorious against Dominic Thiem of Austria 6-4, 6-7, 7-6. 

Several round-of-64 matches also took place today.

Georgian Nikoloz Basilashvili, fresh from his Beijing Open triumph, secured his progress into the round-of-32 after winning 6-2, 6-2 against Denis Shapovalov of Canada.

Britain's Kyle Edmund won his round-of-64 match against Serbia's Filip Krajinović 7-5, 6-3, and Richard Gasquet of France beat Argentina's Leonardo Mayer 1-6, 6-2, 6-1.

The action will continue tomorrow, when Roger Federer of Switzerland and Kevin Anderson of South Africa enter the competition.