By SAM JOHNSTON The Associated Press
Share this story

LONDON — Despite beating Novak Djokovic in straight sets to win the ATP Finals at only 21, Alexander Zverev knows keeping pace with the Serb isn’t going to be easy.

Start Free AccountGet access to 7 premium stories every month for FREE!
Already a Subscriber?Current print subscriber? Activate your complimentary Digital account.
Subscribe NowChoose a package that suits your preferences.