Novak Djokovic retained his place as the No. 1 player in men's tennis following his Sunday U.S. Open victory, while Serena Williams remains atop the women's rankings despite her semi-final defeat at Flushing Meadows.
Williams looked to be on the verge of tennis history with a calendar Grand Slam in sight, but a shock defeat to unseeded Italian Roberta Vinci in the last four stopped the legendary American in her tracks.
However, she remains No. 1 in the world courtesy of a huge points lead over second-placed Simona Halep—and deservedly so, as she is arguably the greatest women's player ever in the sport and has enjoyed a tremendous 2015.
Eventual New York champion Flavia Pennetta jumped from 26th to eighth after she prevailed against Vinci in the final.
|Updated World Rankings|
|1||Novak Djokovic||Serena Williams|
|2||Roger Federer||Simona Halep|
|3||Andy Murray||Maria Sharapova|
|4||Stan Wawrinka||Petra Kvitova|
|5||Tomas Berdych||Lucie Safarova|
|6||Kei Nishikori||Caroline Wozniacki|
|7||Rafael Nadal||Ana Ivanovic|
|8||David Ferrer||Flavia Pennetta|
|9||Milos Raonic||Garbine Muguruza|
|10||Gilles Simon||Karolina Pliskova|
Kei Nishikori suffered the most of the top 10 men. He was knocked out of the U.S. Open in the first round after reaching the final in the same event last year.
He dropped down two places in the rankings from fourth to sixth, with Stan Wawrinka and Tomas Berdych both leapfrogging the Japanese player.
Gilles Simon returned to the top 10 for the first time since 2009, while Rafael Nadal moved ahead of fellow Spaniard David Ferrer.
The top three are unchanged following the year's final Grand Slam in New York, with Swiss legend Roger Federer remaining in second after his final defeat to Djokovic and Scotland's Andy Murray maintaining third spot.
Federer was unable to add an 18th Grand Slam to his career haul on Sunday, as he lost in four sets—6-4, 5-7, 6-4, 6-4—to the ever-resilient Serb, per BBC Sport's Russell Fuller:
Pennetta, 33, announced following her remarkable win in the women's tournament at Flushing Meadows that she would retire at the end of the season despite winning her first Grand Slam and clinching her highest-ever world ranking, per BBC Sport's Piers Newbery.
The end of the year will be in the minds of all the top players after 2015's final Grand Slam, as the season-ending, eight-player tournaments are coming up in October and November.
Williams, Halep and Maria Sharapova have already confirmed their spots at the WTA Finals in Singapore, but the other five places are up for grabs.
Meanwhile, Djokovic, Federer, Murray and Wawrinka are qualified for London's ATP World Tour Finals.
Williams and Djokovic will be the favourites to win their respective season-closers, but with huge pedigree set to be in show in both competitions, such a result is far from guaranteed.