Defending champion Novak Djokovic and Swiss superstar Roger Federer set up a Wimbledon semifinal meeting when each logged quarterfinal wins Wednesday. Both matches were delayed by rain at the All England Club, but the interruptions didn\'t deter the top-seeded Djokovic, who reached the semis with a 6-4, 6-1, 6-4 decision over 31st-seeded German Florian Mayer. The Serb fired seven aces while breaking Mayer\'s serve five times en route to the victory, outpacing the German 50-14 on winners while improving to 44-2 over his last seven Grand Slams. Six-time Wimbledon champ and No. 3 seed Federer, meanwhile, had little trouble with 26th-seeded Russian Mikhail Youzhny, downing him 6-1, 6-2, 6-2 in 92 minutes. The Swiss broke Youzhny six times in the rout, which was witnessed by Britain\'s Prince William and his wife Kate. Djokovic and Federer will meet Friday for the 27th time -- but for the first time ever at Wimbledon. Federer holds a 14-12 career advantage in the match-ups, but the Serb has won six of their last seven meetings.