LONDON (REUTERS) - Britain's Andy Murray can focus fully on next week's Davis Cup assignment in Belgium after Stanislas Wawrinka sent him packing from the ATP World Tour Finals at the O2 Arena on Friday.
The final round-robin match at the year-ender had become a straight knockout between the two players after Rafael Nadal had already sealed top spot in Ilie Nastase Group, and Wawrinka looked the sharper as he won 7-6(4) 6-4.
Earlier, Nadal spent two hours and 36 minutes beating fellow Spaniard David Ferrer 6-7(2) 6-3 6-4 to make sure he went into Saturday's semi-final against world number one Novak Djokovic with a 100 per cent record so far this week.
Wawrinka will face Stan Smith Group winner Roger Federer, who like Nadal was unbeaten in group play.
With Nadal already in the semi-finals and Ferrer going home after two defeats, their match could have turned into a mere exhibition, but the packed arena was treated to the longest match of the tournament so far.
It looked as though the Spaniard might be in for an easy ride when he won 10 of the first 11 points, breaking Ferrer twice, but his 33-year-old opponent is renowned as one of the sport's best battlers and he hit back to win a tiebreak.
World number five Nadal, who had already beaten fourth-ranked Wawrinka and number two Murray, buckled down though and levelled the match before breaking the Ferrer serve in the final game of the contest.
"It should be like this," Nadal, who has been transformed since a modest summer, told reporters.
"Doesn't matter if I was qualified. For me the main goal is to try to arrive in good shape next year. Today was an opportunity to play against another of the top eight players of the world.
"I think I competed well. I won a very tough match. I think a very good match in terms of quality moments."
In the doubles, Ivan Dodig and world number one Marcelo Melo beat Marcin Matkowski and Nenad Zimonjic to set up a semi-final against Rohan Bopanna and Florin Mergea.
Second seeds Jean-Julien Rojer and Horia Tecau will face the Bryan twins after beating French duo Pierre-Hugues Herbert and Nicolas Mahut.