Novak Djokovic said ending 2018 at the top of the rankings would be his "biggest achievement of this year" after he closed in on Rafael Nadal by claiming a record fourth Shanghai Masters title.

The irrepressible Serbian's remarkable resurgence continued when he stretched his winning streak to 18 matches with a 6-3 6-4 victory over Borna Coric on Sunday.

Djokovic will replace Roger Federer as world number two on Monday after claiming a third successive title and is only 35 points behind Nadal.

The 14-time grand slam champion has won Wimbledon and the US Open this year, but would rate heading into 2019 as the world number one as his greatest feat of the season.

"I couldn't ask for a better scenario. I'm very close to Nadal in the rankings and I put myself in a very good position for the last period of the year. " said the 31-year-old.

"We will see, I'm planning to play Paris and London, maybe another tournament before that, maybe not. The game is working really well and ending the year as number one will definitely be the biggest achievement of this year."

Djokovic was in a class of his own in Shanghai and does not feel he could have performed much better.

"The success over the last three or four months has been terrific for me. Not many holes in the game in general, especially this week." he added.

"Everything worked perfectly, I think this was one of the best serving weeks that I had. I think I faced only two, maybe three break points all week, I didn't drop serve all week. That hasn't happened many times, I don't know if it ever happened."