Andy Murray suffered a collapse in form as a rejuvenated Rafael Nadal won their group match at the ATP World Tour Finals in London.<br />Nadal edged a tight first set and then raced clear in the second to win 6-4 6-1 at the O2 Arena.<br />The Spaniard could qualify for the semi-finals on Wednesday, depending on the result of the evening match between Stan Wawrinka and David Ferrer.<br />Murray plays Wawrinka in his last group match on Friday and can still progress.<br />"He was hitting the ball extremely well from the back of the court, but I didn't really help myself," said Murray, who made 29 unforced errors.
