Jannik Sinner will enter the summer hard-court swing in North America as the World No. 1 for the first time in his career.
Sinner is due to defend the Canadian Open this week, which starts on Tuesday. The Italian will retain the world number one ranking after the tournament even if he doesn't win the title.
The 22-year-old's cause has been aided by the withdrawals of Novak Djokovic and Carlos Alcaraz from Montreal after the pair contested an epic Olympic gold medal match on Sunday.
Djokovic, who finally won an Olympic gold medal, will miss the Canadian Open for the sixth year in a row. He had a window of opportunity to reclaim the No. 1 ranking, but he won't do so as he takes a deserved rest after the conclusion of the Olympic Games.
Paris Olympics silver medalist Alcaraz won't play in Montreal and will, therefore, drop 180 points after reaching the quarterfinal last year, although he intends to compete in Cincinnati.
The World No. 1 ranking can still change hands by the end of the US Open, but Sinner is in the driver's seat to hold on that spot. No points were awarded at the Olympic Games, which means that there wasn't a significant change in the Top 10.
Alexander Zverev stayed above Daniil Medvedev in the top four. Hubert Hurkacz climbed up a spot into sixth, while Alex de Minaur dropped to seventh. Both men did not play at the Olympics because of injuries.
Andrey Rublev, Casper Ruud, and Grigor Dimitrov occupy the last three spots in the elite group in that order. Tommy Paul (12th) is ahead of Taylor Fritz (13th) and is the current US men's No. 1.
Fritz dropped points in Atlanta and Washington because of his involvement in the Olympics, where he won a bronze medal in doubles with Paul. And just below them is Ben Shelton who was a semifinalist in D.C.
Four American men are in the Top 20 of the ATP rankings this week. Sebastian Korda's decision to withdraw from the Olympics to start his summer hard-court season earlier has been justified.
The 24-year-old lifted the Citi Open last weekend, the biggest title of his career. He joins his father, Petr, as a champion in Washington. They are the first father-son duo to win the same ATP Tour event.
The younger Korda climbs to a career-high ranking of No. 18. Alejandro Tabilo and Karen Khachanov both exited the Top 20. Frances Tiafoe (27th) looks set to cement his spot as a seed at the US Open but must keep up his good run of form from Washington (semifinalist).
Flavio Cobolli soared to a new career-high ranking of World No. 33. The 22-year-old played in his first ATP final at the Citi Open after a sensational week in which he defeated Shelton, Alejandro Davidovick Fokina, and Alex Michelsen.
Tallon Griekspoor and Daniel Evans lost a lot of ground in the rankings after skipping the Citi Open. The two men contested last year's final, which Evans won, but they were representing their respective countries at the Olympics.
Griekspor drops 12 places to 40th, while Evans leaves the Top 100 and drops as low as 176th. Be sure to check the updated rankings after the Citi Open and the Olympics on our ATP Rankings page.