Fifth seed Nadal defeated fellow Spaniard Fernando Verdasco 6-3 7-5, while ninth seed Federer served impeccably to get past American Stevie Johnson 7-6(3) 7-6(4) and book the 36th showdown of their famous rivalry.
The last time they met, Switzerland's Federer claimed a record 18th grand slam title in a rousing 6-4 3-6 6-1 3-6 6-3 triumph over Nadal in Melbourne in January.
Federer, 35, lost only five points on his first serve in his double tie-breaker win over Johnson in a match completed without a service break.
Fourteen-times grand slam winner Nadal, 30, was comfortable as usual in the California desert, dismissing compatriot Verdasco to keep his Round of 16 date with the Swiss maestro.
