ATP Finals Tennis : Daniil Medvedev, Novak Djokovic Win Matches

Five-time Champion Novak Djokovic and Daniil Medvedev won their matches in ATP finals.

Novak Djokovic overcame an early break to beat Diego Schwartzman 6-3, 6-2 at the season-ending ATP finals.

The top-ranked Djokovic has won the tournament five times — one short of Roger Federer's record.

Schwartzman broke Djokovic for 2-1 in the first set, but the argentine immediately gave it back as he struggled with his first serve.

At 3-3, Djokovic won five straight games to lead by a set and 2-0.

Later on, Russian fourth seed Daniil medvedev claimed a maiden victory with an impressive 6-3 6-4 defeat of Germany's Alexander Zverev.

Medvedev dumped a second serve in the net to lose the opening game but Zverev served three consecutive double-faults in the next game en route to handing the break back.

Zverev won only four of 19 second serve points in the match -- a statistic that ultimately proved costly as the wily Medvedev closed out the victory.