The 20-year-old stunned Swiss great Roger Federer 6-3, 6-4 in Sunday's final to win his second Masters 1000 title of the year, having beaten Novak Djokovic in the Rome title clash in May.
The biggest mover, though, was 18-year-old Canadian Denis Shapovalov, who climbed 76 places to 67th after reaching the semi-finals in Montreal, beating world number two Rafael Nadal along the way.
Briton Andy Murray retained the No.1 spot but will lose it to either Spain's Nadal or Federer at the end of the week.
Murray is injured and will sit out the Cincinnati Masters, where he reached the final last year.
1. Andy Murray (GBR) 7,750pts
2. Rafael Nadal (ESP) 7,555
3. Roger Federer (SUI) 7,145
4. Stan Wawrinka (SUI) 5,780
5. Novak Djokovic (SRB) 5,325
6. Marin Cilic (CRO) 5,155
7. Alexander Zverev (GER) 4,470 (+1)
8. Dominic Thiem (AUT) 4,030 (-1)
9. Kei Nishikori (JPN) 3,285
10. Milos Raonic (CAN) 3,230
11. Grigor Dimitrov (BUL) 3,070
12. Jo-Wilfried Tsonga (FRA) 2,770
13. David Goffin (BEL) 2,560
14. Roberto Bautista Agut (ESP) 2,425 (+2)
15. Tomas Berdych (CZE) 2,390 (-1)
16. Jack Sock (USA) 2,335 (+1)
17. Pablo Carreno Busta (ESP) 2,305 (-2)
18. Lucas Pouille (FRA) 2,220
19. John Isner (USA) 2,110
20. Sam Querrey (USA) 2,060
Selected others:
67. Denis Shapovalov (CAN) 721 (+76)
