TURIN, Italy - Carlos Alcaraz opened his account at the ATP Finals on Wednesday with an entertaining 6-3, 7-6 (10/8) win over Andrey Rublev, while Casper Ruud missed an early chance to reach the semi-finals after losing in straight sets to Alexander Zverev.

World number three Alcaraz comfortably defeated Rublev to lift himself off the bottom of the John Newcombe Group and looked in much better form despite struggling with fatigue and illness in the lead-up to the match.

There had been some doubt as to whether Alcaraz, who lost his opening match in straight sets to Ruud, would continue in Turin after quickly ending his training session on Tuesday, with his coach Juan Carlos Ferrero saying that he had trouble breathing.

"I could be better, I'm not going to lie," said Alcaraz on court after beating Rublev.

"I've been struggling with my health the last week and today I thought I was going to feel better. I was OK to play, but thinking about the first match I was thinking a lot about that I was sick, that I couldn't play.

"Today I really wanted to step on the court and just think about tennis, try to play a high level... When I played the first match I felt like I did not entertain the people, I did not play good tennis."

Alcaraz, who has won the Wimbledon and French Open titles this season, cruised to the first set in 38 minutes, breaking Rublev in game seven and quickly winning the next two to go one set ahead.

And although the Spaniard had a harder time of it in the second set, he delighted the spectators with a series of spectacular shots which suggested he might be approaching his best form.

Ruud misses chance

Rublev meanwhile drops to last place after losing his sixth straight Finals match, although he put up a battle and had two opportunities to win the second set.

Alcaraz winning in straight sets meant that Ruud would have reached the semi-finals with a match to spare if he had beaten two-time Finals champion Alexander Zverev in the day's late match.

However, Zverev put on a punishing display to prevail in straight sets 7-6 (7/3), 6-3 and all-but ensure a spot in the last four with his second win from as many matches.

Zverev took charge of the match in the tie-break at the end of a first set, which before then had gone entirely with serve, and the pair exchanged blows until the German broke in game eight of the second set and then served to love to win the match.

"I think it was a very good match actually from both of us," said Zverev on court.

"I'm happy to win today but it was very, very close. One or two points decided the first set and I thought the level was very high from both of us."

Leader Zverev can eliminate Alcaraz in his final match of the group stage on Friday, when Ruud takes on Rublev.

On Thursday, world number one Jannik Sinner will reach the last four if he claims a single set against Daniil Medvedev, and will top the Ilie Nastase Group with a third straight win.

AFP