The Serb becomes the seventh player in ATP history to finish as year-end No. 1 in three or more seasons.
It was ugly for Andy Murray, but beautiful for Roger Federer, on Thursday in London.
The great Scot handled himself like a trooper in the aftermath of his drubbing at the hands of Roger Federer on Thursday in London.
There are some implications for Li's former colleagues as a result.
Six-time Roger Federer offered his opinion on the one-sided nature of the matches at this year's World Tour Finals.
Not to be outdone by Hunter Reese, Mike Bryan Produces an around-the-netpost gem of his own in London.
Not the best at math? Don't worry tennis fans, we've got you covered with this handy sheet of Group B World Tour Finals semifinal qualification scenarios.