Rafael Nadal came from behind and snatched the victory from the jaws of defeat against Daniil Medvedev to keep his ATP Finals hopes alive and boost his chances of finishing another year as world number one.

The Spaniard was pushed to the brink of defeat before he turned the table around with a spectacular performance to emerge winners 6-7 (3/7), 6-3, 7-6 (7/4).

Both players were under intense pressure after losing their opening round-robin matches in Group Andre Agassi ahead of the match at London’s O2 Arena.

Nadal is hoping for a double delight in London by claiming a maiden ATP Finals title, which has eluded him in his decorated career, and also finishing the season as number one.

Russia’s Medvedev, who has won two Masters titles this season, took the first set on a tie-break to leave Nadal staring down the barrel.

The Spanish veteran broke his 23-year-old opponent early in the second set, repeating the trick to level the match.

Medvedev was first to falter in the shootout, hitting a regulation forehand wide to hand Nadal two match points and he sealed the win on the next point.

In the evening match on Wednesday the two youngest players in the top 10 of the ATP rankings square off, with Stefanos Tsitsipas, 21, taking on defending champion Alexander Zverev, who is 22.

Tsitsipas beat Medvedev for the first time in his career.

Dominic Thiem has already secured one of the qualification spots in Group Bjorn Borg, leaving Roger Federer and Djokovic to scrap it out on Thursday for the remaining place from the four-man pool.

Dominic Thiem put up an enchanting performance to captivate the crowd with a 6-7 (5/7), 6-3, 7-6 (7/5) victory over Novak Djokovic to seal the last four berth at the ATP London Finals.

Thiem played an attacking brand of tennis to leave world number two facing a tough shootout against Rodger Federer.

In the match, which was being billed as game of the tournament so far, the Australian rallied to beat the Serbian after losing the first set.

Earlier, Federer defeated debutant Matteo Berrettini 7-6 (7/2), 6-3 in their round-robin clash to keep his hopes alive of reaching the last four at the season-ending event.

Federer and Djokovic will face off on Thursday in a repeat of this year’s Wimbledon final to determine who else will progress from Group Bjorn Borg. Thiem played a fire-brand tennis in a high-stakes match against the 16-time Grand Slam winner as he spell bound the audience with his inside-out forehands and single-handed backhands. He hit 50 winners compared with Djokovic’s tally of 27 but also racked up 44 unforced errors.

In a captivating first set the players swapped a break apiece but Djokovic, a five-time ATP Finals champion, edged the tie-break.

Undaunted, Thiem broke his opponent at the first opportunity in the second set and, with Djokovic’s error count climbing, went on to level the match.

Thiem also drew first blood in the decider but cracked in the sixth game as Djokovic levelled the match and appeared to have engineered a switch in momentum. The Austrian successfully challenged at 30-30 in the 10th game after his forehand was ruled out, preventing a match point for Djokovic and he toughed it out to level at 5-5.

He then broke Djokovic to love to earn a chance to serve for the match but stumbled and the decider went to a tie-break.

Meanwhile, Czech Davis Cup champion Tomas Berdych plans to announce his retirement from tennis in London on Saturday ending 17 years as a professional.

Agencies