Alexander Zverev battled back from a set down to beat Carlos Alcaraz 6-7 (3/7), 6-3, 6-4 at the ATP Finals on Monday as Daniil Medvedev won a Russian derby against Andrey Rublev in straight sets 6-4, 6-2. Germany's Zverev, a two-time winner at the year-ending tournament, put on a powerful display to see off world number two Alcaraz who is not on top form after returning from injury at the end of last month. Zverev is tough opposition on hard courts like the one at the Pala Alpitour in Turin and made full use of his height and power in the Red Group clash to see off Alcaraz who looks far from being the ageless Novak Djokovic's main rival for the title.
The 26-year-old Zverev rattled off 16 aces and was only broken once over the course of an impressive win in which he hit more winners and made significantly fewer unforced errors than out-of-sorts Alcaraz.
"In the beginning of this year, I was nowhere near at his level," Zverev told reporters.
"I'm just happy to be back at the level where I'm competitive with those guys, where I feel like I can win, I feel like I can compete for tournaments again."
Wimbledon champion Alcaraz has struggled with lower back and left foot problems which had kept him out of action since the Shanghai Masters in early October until the Paris Masters.
He was dumped out early in the French capital by Russian qualifier Roman Safiullin and flagged towards the end of a bruising contest with giant Zverev, the number seven seed in Turin.
However Alcaraz insisted that he was not struggling back to form after his lay-off.
"I'm one of the players who has played most matches on tour... I feel good physically," insisted Alcaraz.
"I don't think I need more matches (to be in top condition)."
Before Zverev's win Novak Djokovic was presented with the trophy for finishing the season as world number one.
'The pinnacle'
The 24-time Grand Slam winner secured that position after winning his thrilling Green Group opener with Holger Rune on Sunday, a match which lasted more than three hours.
Djokovic is red-hot favourite to claim his seventh Finals title which would put him out of his own as the record winner, one ahead of retired great and old rival Roger Federer.
"Winning Grand Slams and being number one in the world are probably the pinnacles of the sport," said Djokovic on court.
Medvedev moved above Zverev -- his next opponent -- to top the Red Group with a straightforward win over his childhood friend Rublev who once again had the worst of a match between the two Russians.
Third seed Medvedev, who has five titles to his name this season, has now won seven of his nine matches with Rublev and needed just one hour and 31 minutes to prevail.
The match turned on the game which would end up handing Medvedev the first set, a 17-point thriller which took more than 10 minutes to resolve and featured four break and set points.
Rublev has had a fine season and won this season's Monte Carlo Masters, but struggles to step up when it counts.
And he lost his head after losing the first set, giving up his serve in the first game of the second and from there allowing Medvedev to cruise to victory to take charge in the group.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)