No. 4 seed Jannik Sinner of Italy improved to 2-0 in round-robin play at the Nitto ATP Finals by taking down No. 1 seed Novak Djokovic of Serbia in a 7-5, 6-7 (5), 7-6 (2) marathon on Tuesday in Turin, Italy.
After losing a 2-0 lead in the second-set tiebreaker, Sinner won the first five points of the third-set tiebreaker to build an advantage that Djokovic would not breach in a match lasting three hours, 9 minutes and 27 seconds.
In an evenly fought match, Djokovic had a 20-15 edge in aces and a 46-37 lead in total winners, but he also committed more unforced errors (14 to Sinner's 11). Sinner broke Djokovic's serve twice, the first coming in the 11th game of the first set as he fought from down 5-4 to win the set 7-5.
Also in Green Group play, No. 6 seed Stefanos Tsitsipas of Greece retired three games into his match against No. 8 seed Holger Rune of Denmark. Rune received the victory and Tsitsipas withdrew from the tournament due to back pain.
"My doctors and the countless visits that I had in the past few days suggested that I play, gave me the green light to go and try it for myself," Tsitsipas said. "Unfortunately, I felt terrible on the court. I did what I could do in the best possible way to be ready and fit for this match, but it didn't work out for me."
Tsitsipas called it a difficult decision to drop out but said it would be a shame not to give his spot to an alternate on standby "to at least try and do something with it."
That alternate will be Poland's Hubert Hurkacz, who will face Djokovic on Thursday instead of Tsitsipas. Hurkacz made his ATP Finals debut in 2021.
Nitto ATP Finals group standings (match win/loss, set win/loss):
Green Group
1. Jannik Sinner (2-0, 4-1)
2. Novak Djokovic (1-1, 3-3)
3. Holger Rune (1-1, 3-2)
4. Hubert Hurkacz (0-0, 0-0)
5. Stefanos Tsitsipas (0-2, 0-4) — withdrawn
Red Group
1. Daniil Medvedev (1-0, 2-0)
2. Alexander Zverev (1-0, 2-1)
3. Carlos Alcaraz (0-1, 1-2)
4. Andrey Rublev (0-1, 0-2)
—Field Level Media