Tennis: Djokovic on track to equal Federer's 6 ATP Finals record

Novak Djokovic won his second straight match at the ATP Finals, beating Alexander Zverev in straight sets to secure his place in semi-finals. Djokovic registered a 6-4, 6-1 victory over Zverev in London. After winning his second straight match Djokovic remains on track to equal Roger Federer's record of six titles at the tournament.