Federer took out Mario Ancic 6-1, 7-5, 6-4 in a rain-spattered match while Nadal dispatched 12th-seeded Andy Murray 6-3, 6-2, 6-4 and earned slots in Friday's men's semifinals. Should they win then, Federer and Nadal, who have played in the last two Wimbledon title matches, would meet Sunday with another Grand Slam crown at stake.
They are both playing as lofty as their rankings. They have lost just one set between them during The Championships and on Wednesday neither faced a break point. Federer allowed Ancic just 10 points on his serve and Nadal limited Murray to 11 points while he was serving.
Federer's semifinal opponent will be unseeded Marat Safin, who on Wednesday knocked off his fourth seeded opponent of the tournament with a 3-6, 7-5, 7-6 (7-1), 6-3 win over No. 31st-seeded Feliciano Lopez. Among Safin's earlier victims was world No. 3 Novak Djokovic in the second round.
Federer is 8-2 lifetime against Safin.
Nadal takes on the winner of the Rainer Schuettler-Arnaud Clement match in the final four. German Schuettler and Frenchman Clement, both non-seeds, were tied at a set apiece, 6-3, 5-7, when play was suspended until Thursday. Officials decided the match was not going to finish Wednesday evening because of darkness.