The final action of the first day of the ATP World Tour Finals saw another debutant, Alexander Zverev come up against Wimbledon finalist, Marin Cilic.
Zverev, 20, battled from a break down in the deciding set to defeat Croatia’s Marin Cilic 6-4 3-6 6-4 in an entertaining encounter.
The 20 year-old who has already won five titles this year, extended his winning run over Cilic to four games at the ATP finals in London yesterday.
Zverev will now face Federer on Tuesday evening as he hopes to become the first German to end the year in the top three.
