After struggling with illness in his opening match, the 21-year-old's throwback sports accessory helped him stay alive at the ATP Finals.
Carlos Alcaraz needs to beat Alexander Zverev to keep his ATP Finals hopes alive, but that is only part of the story.
The win put Carlos Alcaraz back into contention for a spot in the semifinals of the year-ending tournament for the top eight players, after he was beaten by Casper Ruud in straight sets in his opener.