The Canadian fell behind early in the second but twice recovered breaks of serve, and while the 17,000 spectators roared with every punch and counter-punch, Djokovic began to leak errors.

Raonic had lost all seven of their previous matches, and won just one of 18 sets, but he hit 42 winners to 11 as he made the running for much of the two hours and 14 minutes.Дjokovic served well to save three break points in the first set and edged through a gripping tie-break when Raonic double-faulted. 'This definitely can serve as a great wind in the back for the matches to come.' 'Other than a couple of loose service games, I thought it was a good performance,' said Djokovic. He has been the subject of much speculation during a relative slump in form since June, but Djokovic remains a formidable opponent at the O2 Arena.Дespite a fine performance from Raonic, the four-time defending champion made it 21 wins from his last 22 matches in east London to secure a seventh semi-final. Raonic (right) had the chances to secure his first win over Djokovic Djokovic digs deep to deny Raonic Watch: Five best shots as Thiem beats Monfils.Group standings, results, schedule and BBC coverage.Murray will try to join Djokovic in the last four when he plays Japan's Kei Nishikori in the John McEnroe Group on Wednesday, a match that is live on BBC Two, online and BBC Radio 5 live sports extra at 14:00 GMT. Thiem beat Frenchman Gael Monfils 6-3 1-6 6-4 in Tuesday's opening match in the Ivan Lendl Group. Raonic faces Thiem for the other semi-final place on Thursday. The win means the Serb, who beat Dominic Thiem on Sunday, will regain the number one ranking from Briton Andy Murray if he goes on to take the title.

Tennis world tour finals 2016