London's farewell edition of the ATP Finals could still have its dream climax after world number one Novak Djokovic beat Alexander Zverev 6-3 7-6(4) to seal a last-four spot on Friday.
Defeat by Daniil Medvedev had left the five-time champion needing to beat Germany's Zverev to avoid a group stage exit and he obliged with a relatively comfortable win.
Djokovic will finish second in the Tokyo Group, named after the first edition of the season-ending tournament 50 years ago, and with Spanish world number two Rafael Nadal finishing second in the London Group, they have avoided a semi-final clash.
The 33-year-old Serb will face US Open champion Dominic Thiem in Saturday's semi-final, when Nadal plays Medvedev.
Sunday's final will end the tournament's 12-year stay in London before it re-locates to Turin.
Djokovic was soundly beaten by Zverev in the 2018 final, a match played out in an electrifying atmosphere in front of 18,000 fans. This time the arena was empty because of the Covid-19 lockdown, a surreal backdrop for a match with so much riding on it for both men.
Despite the flat feel, Djokovic was quickly into game-mode and when world number seven Zverev double-faulted to drop serve in his first service game he seized control.
Zverev dug in his heels in the second set but missed a chance for an early break before recovering from a couple of double faults to fend off a break point in the following game.
Djokovic looked frustrated at times and twice had to hold serve to stay in the set.
The 17-time Grad Slam champion raised the intensity level in the tiebreak, edging 5-3 ahead with a fizzing backhand pass. He brought up two match points with a hefty first serve before pressurising Zverev into an error to complete victory.
Djokovic is bidding to equal Roger Federer's record of six ATP Finals titles, while Nadal seeks a first.
