Alexander Zverev into ATP Finals semis after straight sets win over Carlos Alcaraz

Turin, Italy: Twice ATP Finals champion Alexander Zverev outclassed four-times major winner Carlos Alcaraz 7-6(5) 6-4 to progress to the semi-finals of the season-ending championship on Friday and leave the Spaniard on the brink of elimination.

German Zverev came into the contest as the group leader with two wins from two matches — against eighth-seeded Russian Andrey Rublev and Norwegian sixth seed Casper Ruud - but needed to win at least one set against Alcaraz to book his place in the semis.

Third seed Alcaraz needed a win of his own, but could still qualify for the semis via percentage of games won - but only if Rublev beats Ruud in straight sets later on Friday.

With the win, second seed Zverev ensured a first-place finish in John Newcombe Group. He will next face U.S. Open finalist Taylor Fritz.

The victory was even sweeter for Zverev, having lost the French Open final against Alcaraz in June.

"He (Alcaraz) beat me too many times this year in important matches, so I'm happy that I got this one," Zverev said.

"Obviously I feel like we have a pretty good rivalry with a great friendship as well, so it's always nice to play against him... Just sharing the court with him. He's a great guy and I'm looking forward to the next matches with him as well.

"It's been three fantastic matches. I'm happy with being 3-0 in the group for sure, but I think now the semi-final is going to be very difficult. (Taylor) beat me the past few times at the slams, so I'm looking forward to that match."

Zverev and Alcaraz failed to find consistency in a tight opening set as momentum swung back and forth before the German came out on top.

Zverev dominated for most of the second set, building a 3-1 lead before surviving a late fightback from Alcaraz.

Zverev won 73% of his points on serve and thumped 29 winners in the one hour and 57-minute contest, taking a 6-5 head-to-head advantage over Alcaraz. It was the world number two's 69th win of the season, the most victories in one season since three-times major winner Andy Murray (78) in 2016.

Since reaching his first semi-final at the ATP Finals in 2018, only record 24-times Grand Slam champion Novak Djokovic (five) has made it to the semis of the tournament more than the 27-year-old German, who has booked his place four times.

Alcaraz, who picked up his first win at this year's ATP Finals when he beat Rublev in straight sets on Wednesday, again wore pink nasal tape, having suffered with respiratory issues in recent days.