The world number one has been dominant in 2025, as he continues to pick up titles on the ATP Tour.
At Wimbledon, Jannik Sinner defeated Carlos Alcaraz in the final to win his fourth Grand Slam title, and his second of 2025.
Choosing to rest up after the tournament, Sinner withdrew from the Canadian Open, as he prepares to return to tennis in Ohio for the Cincinnati Open.
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He’ll do so as the number one seed and defending champion, having beaten America’s Frances Tiafoe in the 2024 final.
However, just days before he returns to action, Sinner has been warned to ‘watch his back’ by his fellow Italian.
Paolo Bertolucci warns Jannik Sinner to ‘watch his back’ with Carlos Alcaraz chasing him
Writing for La Gazetta dello Sport, 1976 Davis Cup winner Paolo Bertolucci shared his thoughts on Sinner’s return.
“Now in Cincinnati, Jannik [Sinner] will need to immediately deliver a high-level performance to consolidate the points he’s gained or make up for those he’ll lose,” he said.
“He’ll have to watch his back from the Spaniard [Carlos Alcaraz], now his only real rival for the world number one spot.
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“The Spaniard has followed the same path as Sinner and will also restart on the scorching American hard courts of Cincinnati, but unlike the Italian, despite being behind in the rankings, he will have very few points to defend in this final stretch of the 2025 season.
“Only two men in command, two players with very different technical and behavioral characteristics, but both aware of the respective strengths of their main opponent.”
Sinner currently leads Alcaraz by 3,430 points in the world rankings, although Bertolucci is right to note that the Italian has a lot to lose over the coming months.
RankNameAge NationalityPoints1Jannik Sinner23Italian12,0302Carlos Alcaraz22Spanish8,6003Alexander Zverev28German6,0304Taylor Fritz27American5,1355Jack Draper23British4,6506Novak Djokovic38Serbian4,1307Ben Shelton22American3,5208Alex de Minaur26Australian3,3359Holger Rune22Danish3,25010Lorenzo Musetti23Italian3,195Official ATP Rankings
Between now and the end of the 2025 season, Sinner must defend over 5,000 points, whereas Alcaraz defends just over 1,000 points.
Jannik Sinner’s points to defend in 2025Cincinnati Open – 1,000 pointsUS Open – 2,000 pointsChina Open – 330 pointsShanghai Masters – 1,000 pointsATP Finals – 1,500 pointsTotal – 5,830 pointsCarlos Alcaraz’s points to defend in 2025Cincinnati Open – 10 pointsUS Open – 50 pointsChina Open – 500 pointsShanghai Masters – 200 pointsParis Masters – 50 pointsATP Finals – 200 pointsTotal – 1,010 points
The pressure will certainly be on Sinner to defend those points, as he looks to finish as year-end number one for the second time in his career.
Year-end number ones on the ATP Tour
Finishing the year as the best player in the world is a remarkable achievement, and one that just 19 players have accomplished since the rankings were introduced in 1973.
Serbia’s Novak Djokovic holds the record for the most year-end number one finishes with eight, while Alcaraz and Sinner sit on one each.
RankNameYear-end #1 finishesYears 1Novak Djokovic82011, 2012, 2014, 2015, 2018, 2020, 2021, 20232Pete Sampras61993, 1994, 1995, 1996, 1997, 1998T-3Rafael Nadal52008, 2010, 2013, 2017, 2019T-3Roger Federer52004, 2005, 2006, 2007, 2009T-3Jimmy Connors51974, 1975, 1976, 1978, 1978T-6Ivan Lendl41985, 1986, 1987, 1989T-6John McEnroe41981, 1982, 1983, 1984T-8Lleyton Hewitt22001, 2002T-8Stefan Edberg21990, 1991T-8Bjorn Borg21979, 1980T-11Jannik Sinner12024T-11Carlos Alcaraz12022T-11Andy Murray12016T-11Andy Roddick12003T-11Gustavo Kuerten12000T-11Andre Agassi11999T-11Jim Courier11992T-11Mats Wilander11988T-11Ilie Nastase11973Year-end number one finishes
It remains to be seen who will finish top of the pile this time around, as it’s almost too close to call.
Sinner may have more to defend between now and the end of the season, but that is, of course, thanks to his excellent performances on hard courts in 2024.
If the Italian can rediscover that form over the coming months, then there’s a strong chance we will see Sinner finish the year as the world number one for the second year in a row.