The Briton secured his semi-final spot by clinching the opening set and went on to complete a comfortable 6-4, 6-2 victory to finish at the summit of the John McEnroe Group.

The result saw him equal his best winning streak of 22 matches and he will go on to face Canada’s Milos Raonic, who he beat to secure the Wimbledon crown earlier this year, in the semi-finals tomorrow.

"He's played very well in this event," said Murray.

"These are quick conditions here and it'll be tough."

Murray, the Wimbledon champion and Olympic gold medallist, showed little sign of fatigue during the encounter with the highly-rated Swiss, winner of two Grand Slam titles, despite a gruelling battle with Japan’s Kei Nishikori on Wednesday (November 16) and emerged victorious from a tense first set.

With his semi-final berth assured, Murray dominated the second as Wawrinka faltered, with the Swiss dropping serve in the opening game.

That helped the home favourite open up a 4-0 lead and he took full advantage, closing out the match in an hour and 26 minutes.

"The first set was tight - there weren't many chances," added Murray.

"I managed to get the break late in the set.

"In the second set I'd already qualified for the semis, so maybe it was easier for me to play more free than him."

Murray’s triumph over Wawrinka enabled him to replicate the three wins recorded by Serbian Novak Djokovic, who he dethroned to take top spot on the rankings, in the group stage.

The Briton must at least match Djokovic’s results if he is to retain his number one ranking.

The Serbian will go up against Nishikori, who concludes the group phase of the season-ending tournament when he faces Marin Cilic this evening in what is a dead-rubber contest as the Croatia cannot qualify for the last four.

Cilic ensured the Japanese player would go into the semi-finals on the back of a defeat as he beat Nishikori 3-6, 6-2, 6-3 to earn his first win at the event.