13:29 CET - It has been a bad start to the day for the fans in Turin, as a brilliant performance from second seeds Henry Patten and Harri Heliovaara has seen them ease to a 6-4, 6-3 win over Italian duo Andrea Vavassori and Simone Bolelli, booking their spots in the doubles final on Sunday!
12:00 CET - Good morning and welcome back to the Tennis Tracker on semi-finals day at the ATP Finals!
The action begins at 14:30 CET, as defending champion Jannik Sinner comes up against Alex de Minaur.
The Italian cruised into the last four with a perfect three wins from three, while the Aussie needed just a single victory to squeeze out of the group.
Unfortunately for De Minaur, he faces a man whom he has played 12 times - and lost on every single occasion. His job will be made doubly hard with the Turin crowd behind Sinner.
Tonight at 20:30 CET, another man who has a perfect record so far at the ATP Finals, Carlos Alcaraz, meets the in-form Felix Auger-Aliassime. The latter won two of his three round robin matches, while losing to Sinner.
Alcaraz leads the head-to-head 4-3 and has won all of their previous four meetings.