Daniil Medvedev eventually overcame Alexander Zverev in a high-quality contest to record his second win of this year's ATP Finals.
The Russian sealed a 6-3 6-7 (3-7) 7-6 (8-6) victory in a tight encounter in which there was only one break of serve, which came in the first game of the match for Medvedev in Turin.
Exactly a year to the day since the two faced each other in the same tournament in London, it looked like history might repeat itself to an even greater extent as Medvedev won the first set 6-3, as he had done in 2020 in a straight-sets win.
The defending champion was dominating from the baseline, but the second set saw a drastic improvement from Zverev, who hit 13 aces having managed just one in the first set.
The German could still not get close to breaking the Medvedev serve, but was able to win the tie-break to level things up.
The third set followed a similar pattern, almost inevitably ending with another tie-break. Despite saving two match points, Zverev could do nothing about the third as Medvedev secured the win and he will qualify if Hubert Hurkacz beats Matteo Berrettini in Red Group later on Tuesday.
Medvedev – 36/27
Zverev – 48/25
Medvedev – 14/1
Zverev – 18/2
BREAK POINTS WON
Medvedev – 1/4
Zverev – 0/4