Roger Federer's Shanghai Masters success saw him rise to his highest ranking since May 2013, as he assumed the No. 2 spot.
The Swiss 17-time major winner claimed his 23rd ATP World Tour Masters-level tournament with a straight-sets win in the final over France's Gilles Simon on Sunday.
Rafael Nadal slipped to third as a result of Federer's win, and the Spaniard's own failure to surpass the second round, where he was beaten by countryman Feliciano Lopez.
Nadal, a 14-time major champion, was suffering appendicitis in China, and could not defend his points gained 12 months earlier when he reached the semifinals at the ATP 1000 event.
The only other change to the top 10 was Marin Cilic's rise to eighth, while Canadian Milos Raonic fell to ninth.
Lopez and Simon were the biggest movers into the top 20, semifinalist Lopez moving up seven spots to 14th while finalist Simon rose 11 places to 18th.
Another player to climb was Russia's Mikhail Youzhny, the Shanghai quarterfinalist up eight places to 27th.
The biggest falls inside the top 50 were those of inactive players - Juan Martin del Potro dropping 10 spots to 29th and Nicolas Almagro also falling 10 to 43rd.
Argentine Del Potro and Spain's Almagro have been sidelined long term due to injury.
On the women's side, Japan Tennis Open champion Sam Stosur did not rise from her 18th ranking after defending her Osaka title.
Other title winners — Czech Karolina Pliskova (up three to 27th, and American Alison Riske (up 18 to 44th) — benefited.
Pliskova won the Generali Ladies Linz in Austria, while Riske claimed the Tianjin Open.
In the top 10, Poland's Agnieszka Radwanska climbed to sixth, exchanging her No. 7 ranking with Canada's Eugenie Bouchard.