Rafael Nadal and Novak Djokovic, who have forged their greatness together over nearly two decades, bowed to youth on the southern bank of the Thames. Despite Andy Murray’s pre-match predictions, Daniil Medvedev and Dominic Thiem, candidates for acclaim among the elite in years to come but still in the queue behind the Spaniard and the Serb, will contest the 12th and farewell London edition of the ATP Tour Finals on Sunday. Murray, sidelined since the French Open with a hip muscle strain, told Gaël Monfils on social media beforehand he favoured Djokovic to beat Thiem and go on to win the final - against Nadal. All change at North Greenwich, then. In the first semi-final, Thiem and Djokovic scrapped like dogs over a bone for nearly three hours of a tense but not great match, although there were many high-grade exchanges. The 25-year-old Austrian won 7-5, 6-7 (10), 7-6 (5), even though the world No 1, whose brilliant season has ended with a slight dip, saved four match points in the second set and was within three points of victory in the deciding shootout. In the evening Nadal, the world No 2, quickly discovered what he might have suspected: this was not the Medvedev he had dismissed for the loss of three games in their first meeting last year, but the vibrant foe who took him to five sets in the 2019 US Open final, then gave him a serious argument here a year ago. The 24-year-old Russian has hit a new peak in recent weeks, arriving with the Paris Masters title. On day six at the O2 Arena, he left with a 3-6, 7-6 (4), 6-3 win, his first over the owner of 20 majors. “I felt really strange when he was serving for the match in the second set,” Medvedev said courtside. “I couldn’t make a good shot in the important moments, which is why I was losing. I made some small changes, going for it a little bit more. “Dominic is playing amazing right now, won the US Open, his first grand slam. I practised with him there twice, centre court. We had good rallies and I said to my coach: ‘I can go far here.’ Now I’m going to see him tomorrow.” In the early stages, Medvedev held easily and Nadal had to fight like a tiger on his own serve – yet he broke to go 5-3 up and serve for the set. After 45 minutes, at 15-30 and 5-3, he looked across the net at an opponent who realised the depth of his dilemma. Nadal – at 34, the oldest player in the tournament and a qualifier for a record 16 times in a row (with six late withdrawals) – grabbed a one-set lead. As well as Medvedev had played behind a wicked serve, Nadal had played better. But 10 minutes into the second set Medvedev was 3-0 up and playing with a freedom born of desperation. A love hold revived Nadal. A break for 3-4 with a fabulous passing shot put spring in his legs. He held and broke again, but Medvedev broke him to love for 5-5, put his foot on the pedal and levelled at a set apiece before pushing on to the line in a combative decider, that did not turn in the Russian’s favour until a charge and smash won him the pivotal seventh game. Each semi-final delivered different statements across the generational divide. “What he did from 0-4 in the third-set tie-break was just unreal,” Djokovic said of his dramatic exit. “I don’t think I played bad. Actually, I made all of my first serves. He just crushed the ball. What can you do? But he deserved it, went for it and everything worked.” Thiem always red-lines his engine in big matches, and this win was no exception. Whether he has got enough to stretch Medvedev even he doesn’t know. “From 0-4, I went for every single shot and every single shot went in,” he said. “It’s not going to be like that in every match, I know that.” He would not complain if he repeated it in the final.