Both Murray and Djokovic won their respective groups by winning all three of their matches in the round-robin portion of the tournament. Murray beat Nishikori, Wawrinka and Marin Cilic while Djokovic beat Raonic, Dominic Thiem and David Goffin (who substituted for Gael Monfils). Murray is now on a 22nd match winning streak, and is now the #1 player in the world. He will face Raonic in the first semifinal (a reprise of the 2016 Wimbledon final won by Murray) and he has won their last 7 meetings and leads the head-to-head 8-3. Djokovic faces Nishikori, whom he has beaten 7 times in a row since losing the 2014 US Open semifinal match, and leads the head-to-head 10-2.
If they both win their semifinal matches the two will face each other for the 35th time, with the year-end #1 ranking going to the winner. Djokovic leads their rivalry 24-10 and has beaten Murray in most of their most crucial meetings (including in 4 major finals) but Murray is playing the best tennis of his life and if there's any time he can turn this rivalry around it is in London while riding a career-high win streak. An exciting end to the tennis year!