Carlos Alcaraz and Jannik Sinner have occupied the men's world number one spot between them for the past 17 months
The battle is about to recommence.
Carlos Alcaraz emphasised it by using two emojis - a number one and a sword fight - in an Instagram post of him posing with Jannik Sinner after their pre-ATP Finals practice on Friday.
Whether Alcaraz or Sinner will finish as the year-end world number one is a key point of interest at this week's season-ending event in Turin.
Ending a long and gruelling season as the best player on the tour is a prestigious accolade, rewarding their brilliance and consistency over the previous 12 months.
