Stanislas Wawrinka
Wawrinak came back from the brink in the first set to reignite his campaign.Getty Images

Stanislas Wawrinka reignited his hopes at the ATP World Tour Finals with a straight sets win to send David Ferrer crashing out at the O2 Arena in London. The two-time grand slam champion prevailed 7-5 6-2 to keep alive his hopes of reaching the semi-final.

Wawrinka recovered from set point down in the first set to win 11 of the next 13 games to underpin his victory. Ferrer looked in command early on but faded badly as the match progressed to end his hopes of reaching the knock-out stage following a second two-set defeat in as many matches.

The result also sees Rafael Nadal join Roger Federer in securing a place in the last four, with the 14-time major winner also assured of finishing top of the Ilie Nastase group with a match to spare after defeating Andy Murray in two sets on Wednesday [18 November]. Novak Djokovic, Kei Nishikori and Tomas Berdych can join them on day five.

Neither player had any margin for error after being convincingly beaten in their opening round robin matches, and having overcome British number one Murray in two sets anything other than a two-set win for Ferrer would see Nadal into the semi-final. Wawrinka had won the last three meetings including their only previous clash at the season-ending tour finals in 2013 but suffered a harrowing defeat against Nadal in his first match of the tournament.

The defeat saw the Swiss number two displays signs of lacking motivation and included huge outpourings of frustration - and similar emotions followed at the start of his duel with Ferrer. The Spaniard grabbed a crucial break in the fourth game and looked set to cruise to the opening set.

Wawrinka's normally imperious backhand was failing him but a moment of complacency from Ferrer allowed the French Open champion back into the match. After a set point came and went for the 33-year-old, a cross-court forehand from Wawrinka put the set back on serve.

Ferrer's missed opportunity signalled a change of momentum and an increasingly patient Wawrinka reeled off five games in a row to break the number eight seed, who was again struggling with his ball toss, and snatch away the opening set. The comeback assured Nadal a place in the last four and Wawrinka too took a stride towards the knock-out phase by claiming the first two games of the second set.

The result appeared beyond doubt when Wawrinka took the third of three break point chances to lead 4-1. Ferrer's impressive court coverage continued and though he successfully served to stay in the tournament, he was powerless to prevent Wawrinka powering to victory from his third match point which propels new impetus into his campaign.