Jannik Sinner says he still has areas where he can improve next year after winning the ATP Finals for the first time Sunday to cap a near-perfect season for the world number one.

Jannik Sinner won the ATP Finals against Taylor Fritz in front of a home crowd. For a man who is still under a doping cloud, Sinner is hitting the cleanest winners.

TURIN, Italy — And so the year ends as it began, with Jannik Sinner’s arms around a big sliver trophy, making a mess of the competition and tennis history for his suddenly tennis-mad country.