Top-seeded Djokovic, Murray steer clear of trouble at Wimbledon Neither No. 1-seeded Novak Djokovic nor No. 2-seeded Andy Murray has lost a set, let alone a match, so far at Wimbledon. The way things have been going at the All England Club this fortnight, that's actually quite an accomplishment. Rafael Nadal, a 12-time Grand Slam champion, was beaten in the first round. Roger Federer, owner of a record 17 major titles, went out in the second round, as did four-time major champ Maria Sharapova. Five-time Wimbledon winner Serena Williams's 34-match win streak ended in the fourth round. And on and on it's gone, with no top-20 player other than Murray left on his side of the draw, and a record-equaling number of withdrawals or mid-match retirements because of health problems. "Everyone was a bit on edge, a little bit uptight," reigning U.S. Open champion Murray acknowledged, "because of what was happening with the injuries, withdrawals, upsets and stuff." He and Djokovic have made it all look so routine, though, heading into the men's quarter-finals Wednesday. On the top half of the bracket, Djokovic - a six-time Grand Slam titlist and the only remaining past Wimbledon winner - will face No. 7 Tomas Berdych of the Czech Republic, the 2010 runner-up, while No. 4 David Ferrer of Spain plays No. 8 Juan Martin del Potro of Argentina, the 2009 U.S. Open champion and the third man yet to drop a set through four matches. On the bottom half, it will be Murray against 54th-ranked Fernando Verdasco of Spain, and No. 24 Jerzy Janowicz against his Davis Cup teammate and pal, 130th-ranked Lukasz Kubot, in a match between the first two Polish men to reach a Grand Slam quarterfinal since 1980. "Magical," Janowicz said. He and Kubot are two of the four men still around who will be playing in the quarter-finals at the grass-court Grand Slam tournament for the first time, along with Verdasco and del Potro. Ferrer lost at that stage last year. The other three have much more solid Wimbledon bona fides: Murray (2012) and Berdych (2010) have been the runner-up, while Djokovic won the title in 2011. I feel good about myself in this moment. I think I actually play better tennis on grass than I played two years ago, when I won this tournament," said Djokovic. " Djokovic has played in seven of the last 10 major finals and he's combined with Federer and Nadal to win 31 of the past 33 trophies. The only other men in those eight-plus years to win a Grand Slam title were Murray and del Potro. Murray has elbowed his way into the upper echelon, turning the Federer-Nadal-Djokovic Big 3 into a Big 4 lately, participating in the finals of the last three major tournaments he entered (he missed this year's French Open with a bad back). The Associated Press