Carlos Alcaraz battled to victory over Taylor Fritz at the ATP Finals on Tuesday, moving to within one win of securing the year-end number one ranking for the second time.

The five-time Grand Slam champion made it two wins from two in the Jimmy Connors Group with a comeback 6-7 (2/7), 7-5, 6-3 victory over last year's runner-up Fritz in Turin.

He will qualify for the semi-finals if Alex de Minaur beats home hope Lorenzo Musetti in Tuesday's second match.

"I'm really happy that I was able to come back, find my good tennis," Alcaraz said. "I just tried to make the most of the opportunities that he gave to me. I think we played great tennis, some great points."

Alcaraz, who was replaced by rival Jannik Sinner as world number one following the Paris Masters earlier this month, will finish 2025 at the top of the rankings if he beats Musetti on Thursday.

Sinner has to successfully defend his Finals title, unbeaten, to have any chance of ending the season as number one for a second straight year.

"I will try not to think about it," Alcaraz said of the year-end number one ranking. "It's going to be a really big match."

Alcaraz now holds a 5-1 winning record against Fritz, whose only win against the Spaniard came at the Laver Cup in September.

The United States' Fritz will face De Minaur in his last group contest. (AFP)