Top-ranked Novak Djokovic started his campaign for a second title at the season-ending ATP World Tour Finals with a win.
The Serb defeated Jo-Wilfried Tsonga of France, 7-6 (7-4), 6-3 in his first group match at London’s O2 arena.
He’ll play U.S. Open winner Andy Murray of Britain in his next group match on Wednesday. Murray, also the reigning Olympic champion, had earlier in the day opened the event with a three-set win against Tomas Berdych of the Czech Republic.
The ATP Finals feature a round-robin format. The top eight players in the ATP World Tour rankings are divided into two groups of four, with the top two in each section moving into the knockout semifinals. Roger Federer of Switzerland is defending champion.