The giant Russian, 24, has now won 10 consecutive matches following his title earlier this month at the Paris Masters and his victory will taste sweet a year after a winless debut in London
The Spaniard, who has never won the elite eight-man event, was beaten 3-6, 7-6 (7/4), 6-3 by in-form Russian Daniil Medvedev, who will play Dominic Thiem in Sunday's final.
ATP Finals 2020: Daniil Medvedev overcomes Rafael Nadal in thrilling semi-final, sets up title clash against Dominic Thiem
Nadal, 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.
Novak Djokovic, five-time winner finishes second in Group Tokyo 2020 behind Medvedev and will play third-seed Dominic Thiem in the semi-finals on Saturday.
ATP Finals 2020: Medvedev downs Djokovic to reach semi-finals; Zverev keeps hopes alive after beating Schwartzman
Daniil Medvedev secured a spot in the semifinals of the season-ending tournament by dominating five-time champion Novak Djokovic 6-3, 6-3 Wednesday for his second straight win of the group stage.
The world number one wobbled at the start of the match against the diminutive eighth seed, making his debut at the elite eight-man event but recovered to win 6-3, 6-2.
ATP Finals 2020: Novak Djokovic vies for sixth crown, Rafael Nadal first as London hosts final year-ending tournament
London hosts its 12th and last ATP Finals tournament headlined by Novak Djokovic and Rafael Nadal but with empty stands. The Serb is seeking a sixth title while the recently crowned French Open winner Nadal is going for his first.
Alexander Zverev says picture painted by former partner is 'not who I am,' apologises for effect of allegations on tennis
Former junior player Olga Sharypova said in a social media post last month that the German world number seven had tried to "strangle" her while at last year's US Open.
The season-ending ATP Finals will be played at the O2 Arena in London for the last time this year. We look at the participants, the schedule and history of the tournament in London.
ATP Finals 2020: Rafael Nadal in same group as defending champion Stefanos Tsitsipas, US Open winner Dominic Thiem
World number one Novak Djokovic will face Daniil Medvedev, Alexander Zverev and Diego Schwartzman in the group stages of the final edition of the tournament in London before it moves to Turin next year.
Novak Djokovic has already clinched the year-end number one ranking for the sixth time as he heads into the ATP Masters starting at London's O2 Arena on Sunday.
Medvedev's first final since last year's ATP Tour Finals saw him come from a set behind to beat Alexander Zverev 5-7, 6-4, 6-1 at Bercy Arena on Sunday.
Paris Masters 2020: Alexander Zverev says he's 'still smiling' despite losing final, assault allegations
Zverev led by a set against Medvedev in his bid for a fourth Masters title on Sunday, but fell to a 5-7, 6-4, 6-1 defeat.
Medvedev was on top form in a high-quality encounter, winning 5-7, 6-4, 6-1 to secure his first trophy of the season and the eighth of his career.
Paris Masters 2020: Alexander Zverev beats Rafael Nadal in straight sets to set up final against Daniil Medvedev
The German claimed his second successive win over Nadal in impressive fashion, easing to a 6-4, 7-5 victory after Medvedev's earlier 6-4, 7-6 (7/4) win over Milos Raonic.
Nadal, who claimed his 1,000th career victory by beating Feliciano Lopez on Wednesday, is bidding for a first Paris indoors triumph which would draw him level with Novak Djokovic on a record 36 Masters titles.
Erste Bank Open: Novak Djokovic saves four set points to beat Borna Coric, virtually assured to end season World No. 1
Novak Djokovic will play either Hubert Hurkacz or Lorenzo Sonego in Friday's quarterfinal.
French Open 2020: Rafael Nadal begins 'most difficult' campaign; Serena Williams eyes elusive 24th Major
Nadal, the undisputed king of clay, needs one more Major to equal Roger Federer's record of 20, but the Spaniard comes to Paris short of preparation and unhappy with the French Open's choice of new balls.
Monfils, ranked ninth in the world, lost 6-4, 6-3 to World No 103 Hanfmann, who had never beaten a top-10 player before.
Italian Open 2020: Injured Serena Williams withdraws; US Open finalists Dominic Thiem, Alexander Zverev also pull out
Four-time champion Serena Williams withdrew from the upcoming Italian Open citing the Achilles issue that bothered her in a loss to Victoria Azarenka in the US Open semi-final