Top-ranked Rafael Nadal overcame a second-set collapse to beat Lukas Lacko of Slovakia 7-6 (3), 0-6, 6-3 Wednesday and join Roger Federer in the quarterfinals of the Qatar Open. Earlier, Federer beat fellow Swiss Marco Chiudinelli 7-6 (5), 7-5. Nadal, who also is playing doubles with Marc Lopez, had a fever earlier this week and looked uncharacteristically slow and sluggish. In the second set, he won just five of 18 points on his serve -- and 11 of 37 overall. "It was a very difficult match," Nadal said. "I wasn't 100 percent yesterday and it was the same today. I said that during the press conference yesterday. I was more tired after I played the doubles matches here. But I will not stop. I will play doubles." It was only the 10th time in 575 career matches that Nadal lost a set 6-0, and the first since the decisive set of a final against Andy Murray at Rotterdam, Netherlands, in February 2009, when the Spaniard was bothered by a knee injury. Read more: http://sports.espn.go.com/sports/tennis/news/story?id=5991859
