Taylor Fritz boosted his hopes of reaching the last four of the ATP Finals with a comeback victory over Australian Alex de Minaur.
De Minaur needed to defeat the American fifth seed in straight sets to have a chance of advancing to the semifinals in Turin, Italy.
However, his hopes were dashed when Fritz stole the second set against the run of play.
Fritz, who then won 5-7, 6-4, 6-3, will advance to the final four of the season-ending tournament if Jannik Sinner beats Daniil Medvedev later on Thursday.
If 2020 champion Medvedev wins in straight sets, the Russian will become group winner ahead of Italian world number one Sinner, while Fritz will be absent.
“We’re all pretty tired, but if I’m in the semifinals of the world tour, I have energy to give,” Fritz said.
Seventh-seeded De Minaur, despite working through his opening service games, was the first to break when he finished a superb rally with a deft crosscourt winner for a 4-3 lead.
Fritz was quick to respond, equalizing in the next game before De Minaur broke again and served out the first set as his opponent grew increasingly frustrated, complaining to the referee about the photograph to the flash in the arena.
The US Open finalist had to fend off two break points in the second set, while De Minaur, by comparison, looked comfortable serving with three love holds.
That was until Fritz increased his intensity and seized his opportunity at 5-4 to end De Minaur’s season.
With his tournament all but over, De Minaur continued to falter as Fritz pounced and he secured victory with an ace after two hours and eight minutes.
“He was all over me. What I did a great job of was towards the end of the second set I started to find my serve, I started to serve better,” Fritz said.
“It just gave me some comfort to stay in the game and not have so much pressure. It was still incredibly difficult.”
Briton Patten continues to win in doubles
Earlier on Thursday, Britain’s Henry Patten and his partner Harri Heliovaara of Finland won three out of three in the doubles event.
The pair, who won Wimbledon together in July, fought back to win 4-6 6-3 12-10 against 2020 champions Nikola Mektic and Wesley Koolhof, who were playing his final match on the ATP Tour.
Patten and Heliovaara, who had already secured their place in the semi-finals, could next face Max Purcell and Jordan Thompson in a rematch of the Wimbledon final.
The Australian duo will advance to the last four if they win against Spanish-Argentine pair Marcel Granollers and Horacio Zeballos later on Thursday.
