A double-Grand Slam winner this season, Alcaraz will be ahead of Sinner in the updated men's rankings on Monday thanks to his success over Musetti which also sealed first place for the Spaniard in the Jimmy Connors Group at the season-ending tournament.

Alcaraz, who has won 70 matches so far this season, could lose his semi-final on Saturday but will now still finish 2025 top of the pile, even if Sinner retains his Finals title on home turf.

But Alcaraz looks in no mood to do that as he seeks his first Finals triumph, and he appears to be on course for yet another final showdown against Italy's Sinner, who qualified in first place from the Bjorn Borg Group on Wednesday.

"It means the world to me to be honest, the year number one is always a goal," said Alcaraz.

"To be honest at the beginning of the year I saw the number one really far away, Jannik being there winning almost every tournament he plays.

"For me it means everything. The work that we put in every day during the whole season, up and downs, comebacks from the tennis side. So I'm really proud of my team and myself."

Alcaraz has won four of his five meetings with Sinner this season, all of which have been in finals of top-level tournaments -- with two deciding Grand Slams.

The 22-year-old won one of the best matches in tennis history against Sinner to retain his French Open title in June before losing the Wimbledon final to the Italian.

And on Thursday he confidently dealt with Sinner's countryman Musetti who has been eliminated and now needs to decide whether to take part in the Davis Cup Final 8, which is being held in Bologna next week.

A passionate crowd cheered on Musetti but it was to no avail for the world number nine who only qualified for the Finals due to Novak Djokovic pulling out at the last minute.

- De Minaur through -

Heading into the semis with Alcaraz is Alex de Minaur who did his part to qualify with a straight-sets win against Taylor Fritz, 7-6 (7/3), 6-3 earlier on Thursday.

Australia's De Minaur had to win in two sets in order to have any chance of making it out of the group, and he will now face Sinner in the semis.

Hard court specialist De Minaur won his 43rd match of the season on the surface, the most on the men's tour, and was too much for Fritz once he prevailed in the first set tie-break.

"Couple days ago was one of the toughest days I've had in my career. I was in a very, very dark spot. I could tell you that I hated the sport," De Minaur told reporters.

"Here we are two days later and I'm feeling great about myself. It's incredible."

De Minaur revealed that personal battle after defeat to Musetti on Tuesday helped his mindset coming into the match with Fritz.

"Regardless of the result today, I had made peace with myself. That was a big, big moment. I knew the way I wanted to play. I was going to commit to it from the first point to the last," he said.

"I was okay with the result not going my way. I had made peace with that. I just wanted to play my way."

Defeat for Fritz in one hour and 35 minutes ended the American's participation in this year's edition of the Finals.