Alexander Zverev has beaten Rafael Nadal in their opening round-robin match of the ATP Finals.
The loss dents Nadal's chances of ending the year as the number one ranked tennis player in the world.
He entered the season-finale in London with an abdominal injury.
Tuesday's match sees Roger Federer, who also lost his opening encounter, take on Italy's Matteo Berrettini.
Play gets underway at 6:00 pm UAE time.
Snow, freezing temperatures force cancellation of games in Germany, England
Two Bundesliga matches have been scrapped due to large amounts of snow and ice blanketing pitches across Germany, while a third-round FA Cup match on Saturday has also been postponed due to freezing conditions in Britain.
Dubai Basketball defeats defending EuroLeague champions
Dubai Basketball has defeated Turkish giants and reigning EuroLeague champions Fenerbahce with a score of 92-81 at the Coca-Cola Arena on Thursday to secure their second victory over the title holders in their debut EuroLeague campaign.
Belgium beat Czech Republic to reach United Cup semis
Zizou Bergs has stunned world number 18 Jakub Mensik and Elise Mertens outplayed Barbora Krejcikova as Belgium beat the Czech Republic 2-0 in the United Cup quarter-finals on Thursday to set up a last-four clash with Switzerland.
PSG clinch French Super Cup after shootout win over Marseille
Paris St Germain have clinched their fourth consecutive French Super Cup title, beating rivals Olympique de Marseille 4-1 in a penalty shootout after a dramatic 2-2 draw in Kuwait on Thursday.
Kyrgios says he won't play in singles at Australian Open
Former Wimbledon finalist Nick Kyrgios has announced on Friday he will not play in the singles competition at this month's Australian Open as he is not ready to play five-set matches.
