Serbia's Novak Djokovic celebrates winning his group stage match against Russia's Andrey Rublev during the ATP Finals in Turin, Italy, Nov 17, 2021.TURIN, Italy — Novak Djokovic advanced to the semifinals of the ATP Finals by beating Andrey Rublev 6-3, 6-2 on Wednesday. The top-ranked Djokovic is attempting to match Roger Federer's record of six titles at the season-ending event for the top eight players in the world. Djokovic was again almost perfect on his serve, although Rub...