LONDON -- Over to you, Andy Murray.Novak Djokovic has got the two group-stage wins he needed to keep alive his hopes of regaining the No. 1 spot this week. He beat Milos Raonic 7-6 (6), 7-6 (5) in Tuesdays Tour Finals evening session to ensure he will be around for the weekend at the O2 Arena.Now all he needs to do is win a fifth consecutive title -- and sixth overall -- here to finish as year-end No. 1, if it comes down to a winner-takes-all shootout with Murray in Sundays final.There are other permutations by which Djokovic, who was overtaken in the rankings by Murray last Monday after 122 weeks, can finish the year on top but he knows his fate is still in his own hands.I have never felt unbeatable and I never will, the Serb told a post-match news conference. I dont feel vulnerable, he added, however, which could be a concern for Murray.Djokovic is perhaps the closest thing you can get to a sure bet against Raonic, having now won 18 of the 19 sets they have played over eight meetings.Raonic had his chances here, though. The Canadian failed to take two break points in the third game of the opening set, and was made to pay when Djokovic edged a tiebreaker after 64 minutes of play at the O2 Arena.After twice breaking the Djokovic serve to level the second set, Raonic then wasted a set point at 6-5 before the Serb came out on top in another tiebreaker to seal the win in two hours, 13 minutes.It was a very close match. Very few points separated us tonight. It really could have gone either way, added Djokovic.I was fortunate to get through the first set tiebreaker. I was down very early in both tiebreaks tonight. But I just managed to stay committed and put pressure on his second serves.But I should have done my job earlier, to be honest. Im not very pleased to drop my serve twice [in the second set] against Milos, especially the second time. I was 4-3, 30-Love, then just four pretty bad unforced errors.Credit to him for really hanging in there, putting pressure, being aggressive, especially from the forehand. But, you know, I think I should have done better there.Gael Monfils was earlier beaten 6-3, 1-6, 6-4 by Dominic Thiem in Tuesdays afternoon session at the O2 Arena.Not my best, was the Frenchmans blunt assessment of his fitness out there, having suffered an apparent knee injury and been sprawled flat out on his back at one point.Thiem went a set up in just 25 minutes here, with Monfils winning just five points on the Austrians serve. The 30-year-old was hobbling around in pain, toiling at the baseline and unable to slide and chase down what the Austrian was throwing at him to full effect.Monfils did race into a 4-0 lead in the second set, however, forcing the decider with Thiem threatening to crumble again like he did after winning the opening set against Djokovic Sunday.But a Monfils double fault gave Thiem match point in what had been a close-fought third set, and a long forehand ended the contest.I give my best, as usual, fighting with everything I had, he added. Thats the only matters when you step on the court.After a second defeat in two matches, it is fair to wonder whether Monfils will play his final round robin match Thursday against Djokovic, with alternate David Goffin waiting in the wings.I will try to recover because obviously Im not good enough to play back-to-back. So hopefully, you know, Ill be much better, said Monfils.With his first Tour Finals victory, Thiem kept his hopes of making the semifinals alive. He next faces Raonic Thursday.Very happy that when Im facing him that theres still something going