Rafa Nadal produced one of his best performances of the year to beat Andy Murray 6-4, 6-1 at the ATP World Tour Finals and move within sight of the semifinals Wednesday. The 29-year-old 14-time Grand Slam champion looked more like the dominant player of old as he edged a tight first set at the O2 Arena before running away with the match. With two wins out of two the Spaniard will be assured of one of the top two places in the Ilie Nastase Group if Stanislas Wawrinka beats David Ferrer in the later match. Murray, who beat Spaniard Ferrer in his opener, faded badly in the second set after Nadal finally broke serve decisively in the 10th game having wasted several earlier opportunities. Britain's world No. 2, who has one eye on next week's Davis Cup final in Belgium, looked distracted, surrendering nine points in a row early in the second set, and Nadal needed no second invitation to press home his advantage. Murray, who bizarrely trimmed his fringe during a changeover in the first set, can still reach the semis by beating Wawrinka in his final round-robin match Friday. Resurgent Nadal's late-season form, including finals in Beijing and Basel, have lifted him to fifth in the world rankings, having fallen to 10th during a torrid summer. Murray was struggling, both with his serve and his hair, during the match. He gave himself a little trim during a changeover in the first set, but on the court he found it difficult to improve. Murray and Nadal traded breaks to open the match, and then Nadal held to make it 2-1. During the changeover, the second-seeded Murray pulled out a pair of scissors and clipped off a few strands of hair. "I had some hair in my eye, and I just wanted to get rid of it," said Murray, clearly annoyed with the line of questioning. "That literally took two seconds. That was it." On Tuesday, Roger Federer stopped Novak Djokovic's ATP Finals winning streak at 15, beating the top-seeded Serb 7-5, 6-2 to reach the semifinals. Djokovic, who has already clinched the year-end No. 1 ranking, had not lost at the ATP Finals since 2011, winning the last three elite titles for the top eight players in the world. But Federer was strong at the O2 Arena, as he usually is on an indoor hard court. The six-time champion broke Djokovic in the final game of the first set, and again early in the second. Although Djokovic broke right back, Federer regained the lead a short time later and won the final four games. On Sunday, Federer beat Tomas Berdych, giving him a 2-0 record. He will still play Kei Nishikori Thursday in the final round-robin match. Djokovic beat Nishikori in his first match, and will face Berdych Thursday for a spot in the semis. "Still to me Novak is the favorite for the tournament," Federer told reporters. "He's far from gone. The way I know Novak, he's going to find a way to be tougher to beat from now on." — Agencies