Novak Djokovic beats Milos Raonic to keep No. 1 hopes alive

— -- 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 Tuesday's Tour Finals evening session 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, and it could come down to a winner-takes-all shootout with Murray in Sunday's 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.

It was the same old story for Raonic, who has now taken just one set off Djokovic in the 19 they have played across eight meetings.

He had his chances here. 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.

Gael Monfils was earlier beaten 6-3, 1-6, 6-4 by Dominic Thiem in Tuesday's afternoon session at the O2 Arena.

"Not my best," was the Frenchman's 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 Austrian's 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. "That's 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 I'm not good enough to play back-to-back. So hopefully, you know, I'll 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 I'm facing him that there's still something going on," Thiem said in an on-court interview. "Potentially I have the chance to reach the semifinals. Just try to get fit again for the last match and go."