Rafael Nadal slipped out of the top three in the new ATP rankings released on Monday while Jannik Sinner, who won the Washington tournament at the weekend, jumped nine places to 15.
The 20-time Grand Slam winner Nadal lost to Lloyd Harris in the round of 16 in Washington to find himself dropping one place to number four with the Greek Stefanos Tsitsipas replacing him at three.
Italian teenager Sinner, who beat the American Mackenzie McDonald in three sets in Washington, climbs from 24th into the higher realms of the game’s elite.
Sinner, who only turns 20 on August 16, is the youngest player to win an ATP 500 tournament since the category was created in 2009.
By reaching the final, McDonald also enjoyed a dramatic leap from 107th to 64th.
Novak Djokovic, who has won all three majors this year and has his eyes firmly set on completing the sweep with another success at the US Open, remains comfortably at number one.
The Serb has now spent a record 333 weeks in top spot, well ahead of next-best Roger Federer, who managed 310 and is now down at number nine.