Beno Udrih made a big 3-pointer in the closing minutes, too, and the Kings won their third straight.
Jason Thompson added 15 points and Dalembert finished with 13. The Sixers were led by Jrue Holiday's 28 points and Jodie Meeks added 22. Philadelphia missed a chance against one of the NBA's worst teams to make up ground on fifth-place Atlanta.
The Kings trailed by five at halftime, but Thornton's 19-point third quarter helped get them out of the hole.
Trailing 91-87 with 4:58 to play, Holiday scored the next nine points for the Sixers - capped by a 3-pointer - to put Philadelphia up 96-91 with two minutes left.
Sacramento quickly tied it again after Marcus Thornton drilled a bucket, then a 3-pointer with 36.6 seconds to play.
Note: Evans played in his second game since missing the previous 19 with left foot plantar fasciitis, scoring 10 points in 23 minutes.