Nitto ATP Finals: Andrey Rublev fights back from a set down to reach the semifinals in Turin

Stefanos Tsitsipas began the opening round of the winner takes all match aggressively and won 3-6 to put pressure on Andrey Rublev. 

However, the 25-year-old Russian maintained his composure and retook control with his explosive groundstrokes to force the match into a decider before eventually securing his 51st tour-level win for the season after one hour and 32 minutes of play.

World No. 7 Andrey Rublev served ten aces, won 79% of the points on the first serve and broke the serve of his Greek opponent three times from five opportunities. 

In contrast, Stefanos Tsitsipas served ten aces, won 75% of the points on the first serve and earned one breakpoint from three opportunities.

After the victory, Andrey Rublev said, "I kept fighting. I just kept saying to myself, 'It doesn't matter how he's playing, how good he's playing, just fight for every ball.' In the end, I was able to start to play better and better. In the end, I was able to turn around the match. I'm happy."

Andrey Rublev will next lock horns with Norwegian sensation Casper Rudd in a semifinal clash of the Nitto ATP Finals on November 20.

 It will be the first time Rublev has advanced to the semifinals at the ATP Finals after crashing out in the group stage in his previous two appearances.

Novak Djokovic is pushed to his limits by Daniil Medvedev in the Turin thriller and keeps his unbeaten title hopes alive.

Former World No. 1 Novak Djokovic of Serbia fended off a tough challenge from Daniil Medvedev to beat Daniil Medvedev 6-3, 7-6(7-5), 7-6(7-2) his final group-stage clash of the Nitto ATP Finals on November 18.

Novak Djokovic had already advanced to the semifinal round of the Nitto ATP Finals before he clashed with Daniil Medvedev. However, he left no stone unturned to survive a three-set marathon match to top Group Red with three wins.

The 35-year-old Serbian legend was pushed to the brink by Daniil Medvedev. After winning the match, Novak Djokovic said, "Everyone has one of those days where they struggle more physically. For me that was today. Well, it was just fatigue from a grueling battle. That's all I can say. I mean, there was no illness."

Novak Djokovic is aiming to win the Nitto ATP Finals title for the sixth time in a row, having last won the title in 2015. He will next clash with Taylor Fritz in the semifinal round of the ATP Nitto Finals on November 19.