WATCH the ATP Finals LIVE in Australia on beIN SPORTS | Subscribe here and take advantage of our 7-day FREE TRIAL

The Spaniard downed two Italians with one strike, eliminating Musetti from the season-ending championships and railroading Jannik Sinner's hopes of regaining top spot in the rankings despite a far from stellar performance in his third round-robin win from three.

"The match was really important for me, playing for year-end number one," Alcaraz said.

"It wasn't easy at the beginning with the nerves. I tried to handle that pressure the best I could, so I'm just really happy with the level I played and to be able to end the year as the number one."

Alcaraz, who previously ended the year at top spot in 2022, has had the best season of his career, reaching the final of three grand slams, winning the French and US Open and losing the Wimbledon decider, facing Sinner on all three occasions.

The 22-year-old, who won eight titles in total this season, remains on course to win his first ATP Finals after overcoming a brave Musetti performance, where Alcaraz broke at 5-4 up in the first set before comfortably winning the second.

Alcaraz and Sinner could well do battle one final time this year, with the Italian already into the other semi-final as winner of the Bjorn Borg Group before his win over Ben Shelton to top the other group.

"This tournament is really important for me," Alcaraz added.

"I'm excited about qualifying for the semi-finals and hopefully getting to the final. We will see, part of the job is done, but I'm excited to keep going."