The tennis greats each had straight-sets victories Saturday to set up a Swiss Indoors title match that is their first on-court meeting since January 2014, and first final since May 2013.
"It's fantastic for the fans, for the tournament … and for both of us," said the top-seeded Federer, after easing to a 6-3, 6-4 win against unseeded American Jack Sock in the semifinals.
Earlier, the third-seeded Nadal played his best tennis of the week in beating Richard Gasquet of France, 6-4, 7-6 (7).
Petra Kvitova will play for her second WTA Finals title after defeating third-seeded Maria Sharapova, 6-3, 7-6 (3), in the semifinals at Singapore. The fourth-seeded Kvitova, who won this title on her first attempt in 2011, plays fifth-seeded Agnieszka Radwanska in the final. Radwanska advanced to the final for the first time in seven appearances, beating second-seeded Garbine Muguruza, 6-7 (5), 6-3, 7-5.
Sharapova had a 5-1 lead in the second set but couldn't push the match into a decisive third set. She served for the second set in the eighth and 10th games, but didn't reach set point in either.
Joao Sousa advanced to the final of the Valencia Open in Spain after beating Vasek Pospisil, 6-4 6-4.