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.
Mac Allister heads Liverpool to Champions League win over Real Madrid
Liverpool's Alexis Mac Allister headed a second-half winner as the hosts earned a hard-fought 1-0 victory over Real Madrid in a battle between European giants on Tuesday, handing the LaLiga leaders their first defeat in the Champions League this season.
Sabalenka overpowers Pegula, Gauff eliminates Paolini in WTA Finals
World number one Aryna Sabalenka earned a 6-4 2-6 6-3 win over Jessica Pegula, while defending champion Coco Gauff put on a clinical performance to beat Jasmine Paolini 6-3 6-2 and eliminate the Italian in Riyadh on Tuesday.
Pakistan win ODI against South Africa in last over as Salman shows the way
Salman Ali Agha top scored for Pakistan as they snatched a last-over victory over South Africa on Tuesday in an exciting finish to the first of three One Day Internationals at Faisalabad.
David Beckham knighted for services to sport and charity
David Beckham, one of Britain's most celebrated football players, was knighted by King Charles at Windsor Castle on Tuesday, recognising his decades-long contribution to sport and charitable causes.
Aryna Sabalenka challenges Nick Kyrgios in Dubai showdown
Tennis fans are in for a treat this December as WTA World No. 1 Aryna Sabalenka takes on showman Nick Kyrgios in a one-off exhibition match, Battle of the Sexes: The Dubai Showdown.
