Top seed Novak Djokovic started his bid for a record-equalling sixth ATP Finals title with a classy win over Argentine debutant Diego Schwartzman.

(The New York Times)

The 33-year-old Serb, who has not won the event since 2015, eased to a 6-3 6-1 victory at the O2 Arena in London.

"The second set I started swinging through the ball more and with less hesitation," Djokovic said. "I was very pleased with the way I played."

Daniil Medvedev and Alexander Zverev meet in the same group later on Monday.

The season-ending event is being played behind closed doors because of the coronavirus pandemic.

That has led to a flat and eerie atmosphere at the near 18,000-seat arena, meaning London has been unable to wave farewell to the event - which moves to Turin in Italy next year - like tournament organisers would have intended.

"Everything is difficult against Novak," Schwartzman added. "When he is playing his best he is moving the ball everywhere on court in every single point."

(Lupni.com/BBC)