The Pistons have lost all of their five games this season and remain one of two winless clubs in the NBA. Washington fell to 0-3 earlier in the evening.
Detroit trailed from the middle of the first period to the end of the game, but the Pistons stayed close throughout and were within two points after Brandon Knight's 3-pointer with 28 seconds left.
Fredette's foul shots put Detroit up by four and a missed 3-point attempt by Kyle Singler with 10 seconds remaining ended the Pistons' hopes.
Sacramento won for the second time in five games with all three of its losses having come on the road.
Knight and Greg Monroe both had 21 for the Pistons, who are four games into an early-season, six-game road trip that will continue with visits to Oklahoma City and Houston.