Andy Murray
Andy Murray plays a forehand volley during his win over Stan Wawrinka at the ATP World Tour FinalsReuters

Andy Murray has no plans to let go of that No.1 ranking. Needing a win to ensure there would be no drama over a semifinal place, Murray put his best foot forward to ease past Stan Wawrinka and lock a place in the final four of the year-end tournament in London.

Murray had won his first two matches, but those wins had still not guaranteed him a place in the semifinals. However, the world number one made sure there would be no doubts with a 6-4, 6-2 victory over the Swiss, a win which ensured his place as the group topper.

"I weathered the early storm a little bit," Murray said. "Stan came out hitting the ball huge. He was hitting a lot of winners, a lot of aces. But once I got through the early part of the match, I started to create chances in most of his service games.

"I served very well myself, got a lot of free points with my serve. That allowed me to also dictate a lot of the points, whereas at the beginning of the match I wasn't able to do that."

Murray will face Milos Raonic in the semifinals, which means a possible final against Novak Djokovic is still in play. Joining Murray from Group John McEnroe is Kei Nishikori, who came through despite losing two of his three matches.

Nishikori, who began the ATP World Tour Finals with a thumping win over Wawrinka, went on to lose his next two, including the one against Marin Cilic on Friday. Cilic beat the Japanese player 3-6, 6-2, 6-3, but both players knew, by then, after Murray had beaten Wawrinka, that Nishikori would be the one to move into the semifinals.

Next up for Nishikori is a final four match against Djokovic. "I just tried to focus on (Friday's) match," Nishikori said. "Unfortunately, it was a tough loss. But hope I can play better (on Saturday).

"I will try to think what I have to do to beat Djoko. I mean, I'm obviously not playing bad."