Carlos Alcaraz said securing the year-end world number one ranking "means everything" after he reached the knockout stages of the ATP Finals with three straight wins.

Alcaraz was already assured of a semi-final place, after Alex de Minaur beat Taylor Fritz earlier on Thursday - but he would not be denied in his bid to edge rival Jannik Sinner in the race to be crowned the top-ranked men's player of 2025.

The 22-year-old Spaniard let out a huge roar as he achieved the feat by beating Italian ninth seed Lorenzo Musetti 6-4, 6-1, also ensuring he recorded 70 wins in a season for the first time in his career.

In topping the Jimmy Connors Group, Alcaraz has avoided a semi-final meeting with Sinner, who is already confirmed as the winner of the Bjorn Borg Group before the final round of matches on Friday.

Sinner will play De Minaur in the last four, while Alcaraz awaits the winner of German Alexander Zverev and Canada's Felix Auger-Aliassime, as the world's top two aim to set up a tantalising final blockbuster showdown to conclude a year in which they have once again dominated the tour.

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

"At the beginning of the year, I saw number one really far away, with Jannik winning almost every tournament he plays.

"Then in the last three, four tournaments of the year, [I was] fighting toe-to-toe with Jannik for this spot, and then finally I got it. For me, it means everything."

Alcaraz will end the year top of the rankings for the second time, having become the first teenager to achieve that feat in 2022.

In addition to his tour-leading 70 wins, Alcaraz has also achieved an unmatched eight titles in 2025 - including two Grand Slams - equal to his total number of losses.

Now he will seek to complete another stunning season by winning the ATP Finals for the first time.

Musetti was backed by a passionate home support inside a packed 12,000-capacity Inalpi Arena, as he sought to build on the momentum of his dramatic victory over De Minaur on Tuesday.

The Italian, battling fatigue in his seventh match in nine days following his run to the Athens Open final, matched Alcaraz deep into the opening set - but his admirable resistance was eventually ended in an absorbing 11-minute 10th game.

Although Musetti continued to dig in, withstanding a break point in his opening service game of set two, his relentless opponent continued to apply pressure and broke to love for a 3-1 lead.

That sparked Alcaraz's dash to the finish line, but only after a free-hitting Musetti created his first two break points to re-energise the crowd.

That excitement was short-lived as Alcaraz fired back with four consecutive points, and there would be no recovery for a fading Musetti, who was broken again before Alcaraz served out victory to achieve the first of his goals in northern Italy.

De Minaur recovers from 'dark place' to progress

De Minaur was among those willing Alcaraz to victory after maintaining his interest in the season-ending competition, despite opening with back-to-back defeats.

The Australian said he had recovered from "a dark place" following his painful loss to Musetti, in which he held a 5-3 lead in the deciding set before losing four consecutive games to concede the match.

Requiring a straight-set victory to remain in contention two days later, De Minaur ended American sixth seed Fritz's tournament with an impressive 7-6 (7-3) 6-3 win.

"It means a lot. A couple of days ago I was in a pretty dark place," De Minaur told Sky Sports.

"More than anything, I feel proud of my efforts. Not for just coming out and winning, but also the mindset. I made peace with what had happened and just committed."

De Minaur was reluctant to trust the news that he would qualify with an Alcaraz win when he was initially informed in his post-match interview.

The 26-year-old had lost his past 16 matches against top 10 players, and each of the five matches he had previously played at the ATP Finals. The latest loss to Musetti had rocked his confidence.

But, against an opponent whom he had lost the two previous meetings, De Minaur reset mentally to produce an inspired display against Fritz.

Before leaving the court, he wrote 'finally' on the TV camera lense.

"I've dealt with a fair bit of heartbreak recently," De Minaur said in his post-match interview.

"[The loss to Musetti] was a tough pill to swallow. I didn't overthink today, I just went out and committed to what I needed to do. I continued to back myself and, whether it worked or it didn't, I was going to leave it all out there today."

In the men's doubles, world number one pairing Julian Cash and Lloyd Glasspool set up an all-British semi-final against Joe Salisbury and Neal Skupski by beating Marcel Granollers and Horacio Zeballos 6-3 7-5 to finish second in the Peter Fleming group.

Fellow Briton Henry Patten and Finnish team-mate Harri Heliovaara will seek to join them in the knockout stages when they face Marcelo Arevalo and Mate Pavic on Friday.