ANDY Murray refused to blame a bad hair day for his 6-4, 6-1 defeat to Rafa Nadal at the ATP World Tour Finals in London. The Scot took advantage of a change of ends to take a pair of scissors from his bag and trim an unruly lock of hair from his brow during this defeat at the round robin stage, which leaves him requiring a victory against Stan Wawrinka on Friday to be sure of his place in the last four. While the World No 2 admitted the troublesome curl had been getting in his eyes, he said in the grand scheme of things that it was merely a detail in his defeat to the resurgent Mallorcan.

"I don't know why such minor things make such a big deal to you guys," said Murray. "I had some hair in my eye, and I just wanted to get rid of it. That literally took two seconds. That was it. It was nothing to do with next week [the Davis Cup final] or anything to do with the outcome of this match. I started the match extremely well, I think. I played a very good first game. Although I got broken in the second game, it was a good game. I was hitting the ball well. I held all the way through to 4-All from that change of end. So it wasn't like it was something that affected me at all after it happened."

Of more relevance to the defeat was a first serve percentage which stood at just 43%. With Nadal winning two thirds of all points on his second serve, that was a recipe for disaster against the Mallorcan, who seems to be approaching his best form after spending much of 2015 gradually working his way back from illness and injury.

"He obviously played better today than he did when I played him earlier in the year [in Madrid]," said Murray. "Obviously he's won a lot more matches in the second half of the year. He's clearly playing better tennis now than a few months ago. Also I didn't help myself out there. I served an extremely low percentage, maybe lowest percentage I served the whole year in any match. That's not good enough against someone as good as Rafa."

The Scot, who now faces the French Open champion Wawrinka both to prolong his interest in this tournament until the weekend and secure his status as year-end World No 2, appeared to be suffering from tightness in his hamstrings towards the end of the match but said he felt physically fine afterwards. With Roger Federer, and not Novak Djokovic, currently leading in Group Stan Smith and waiting for the second placed finisher in Group Ilie Nastase, he also felt moved to deny that he hadn't been too concerned about winning as he had another chance to qualify to come or that his thoughts were racing ahead to next weekend's Davis Cup final.

"I think the way the format is, almost every game is important," said Murray. "Rather than thinking like, 'oh, well, I can just lose this set, it's fine'. I've never looked at any of the matches like that. You certainly don't want to lose to one of the guys that you're competing against in the biggest events for the biggest titles in the sport quickly in the second set.

"I'm obviously disappointed with the way the match finished. I'm not trying to finish second in the group. I'm trying to win every match that I play."

"It was a fortunate day for me - one of my best days of the season without a doubt," said Nadal. "I think I played well in general. The tactic against Andy is always 'play very well'. He has all the shots so the only way to damage him is to play with high intensity. It is important for me to see these results in competitions after a lot of work."