Daniil Medvedev beat Rafael Nadal after a gruelling slugfest at the ATP Finals in London on Saturday to set up a title match against Dominic Thiem.
The Spanish world No 2, who has never won the elite event in his illustrious career, faltered when serving for the match in the second set and was beaten 3-6, 7-6 (7/4), 6-3.
Russian giant Medvedev – who has won nine matches in a row – put Nadal’s serve under intense pressure in the early stages of their evening match at the empty O2 Arena.
But he was unable to make his chances count and a drop in his level allowed the Spaniard to break to love to lead 5-3 before he served out for the set.
Medvedev immediately found his focus at the start of the second set, winning his first service game to love before Nadal, a two-time finalist at the event, double-faulted to give the Russian a 2-0 lead.
Just when it seemed as though Medvedev was cruising, Nadal, 34, broke back twice to take total control and stepped up to serve for the match.
But in another astonishing twist, the 20-time Grand Slam champion played a sloppy game, allowing the Russian back into the match, and Medvedev won the eventual tie-break.
The deciding set hinged on the seventh game – the Russian produced an overhead winner on his third break point, breaking again to beat Nadal for the first time.
Earlier, US Open champion Thiem recovered from 4-0 down in the third-set tie-break against Novak Djokovic to win 7-5, 6-7 (10/12), 7-6 (7/5).