Carlos Alcaraz has regained the No. 1 ranking from Jannik Sinner after winning the 2025 US Open, beating the Italian in four sets to win his second Grand Slam of the year. The duo has shared all the last eight Grand Slams between them, with Alcaraz winning Roland Garros and the US Open this year.Sinner will now make his debut in Beijing, featuring in the China Open. Meanwhile, due to conflicts in schedule, Alcaraz has decided to play in Tokyo for the Japan Open. Both tournaments are happening in the same week. In a press conference, Sinner gets honest about losing the No. 1 ranking to the Spaniard."Not being number one add or take away any pressure from. The season has gone as it has: yes, we've shared the Grand Slams, but even so, they have been two very different seasons. Carlos deserves to be there. He has played more tournaments and all at a very high level of tennis. We still have this tournament left, two Masters 1000s, Turin (ATP Finals), and the Davis Cup."Sinner will be the top seed in the China Open, which runs from September 25 – October 1, 2025. The ATP 500 tournament will be played on hard court. Meanwhile, Alcaraz is the top seed in the Japan Open, which runs from September 24 – September 30, 2025.Can Jannik Sinner regain No. 1 ranking from Carlos Alcaraz before the year ends?Currently, Carlos Alcaraz leads Jannik Sinner by about 760 points in the rankings race. In addition, the Italian has more avenues to see a drop in points with big tournaments to protect from last year. It appears Alcaraz is in control of the year-end No. 1 race, as he has fewer "defending points" late in the season while Sinner has more at stake.However, there's a slight chance Sinner can achieve the No. 1 ranking. This will require him to reach the latter rounds (or win) in the remaining Masters 1000 events (e.g., Shanghai, Paris) and at the ATP Finals. Moreover, in the tournaments where Alcaraz is also performing, Sinner must go one round further.Before regaining the No. 1 title, Alcaraz said he doesn't focus too much on rankings, as it will add undue pressure.“It’s really hard not to think about it,” Alcaraz said via Tennis365. “Every time I step onto the court, I try not to focus too much on it. If I think about it too much, I’ll put too much pressure on myself. I just want to show up on the court and do what I have to do each time, which is to meet my goals and win the match, while having as much fun as possible.”It remains to be seen if Sinner regains the No. 1 ranking in the near future.