Andy Murray crushed Stan Wawrinka 6-4 6-2 to win his group at the ATP World Tour Finals on Friday and stay on course for a season-ending climax with Novak Djokovic.

What initially promised to be a tough afternoon for the world number one against the burly Swiss turned into a stroll for Murray, who extended his winning streak to 22 matches and set up a semi-final against world number four Milos Raonic.

U.S. Open champion Wawrinka was seeking to reach the semis for the fourth consecutive year and was full of aggression in the early stages.

But a netted volley gave Murray a break in the seventh game. The Swiss saved three set points at 3-5 but Murray was bossing the match by then and held serve in the next game.

The Scot streaked away with two breaks of serve in the second set, with Wawrinka demolishing two rackets after falling 3-0 down.

After spending three hours and 20 minutes grinding past Kei Nishikori on Wednesday, Murray was in no mood for any overtime and quickly polished off his man.

Murray's 22-match streak equals his run earlier in the season. Two more wins here would deliver his maiden ATP World Tour Finals title and the year-end number one ranking for the first time.

Four-times defending champion Djokovic, whose 122-week stay as world number one was ended last week, also won his three group matches and will face Japan's Nishikori in the other semi-final.