Oklahoma (14-2, 4-0 Big 12) led 52-48 with 4:48 remaining when Ellenberg hit a 3-pointer, jumper and 3-pointer on consecutive possessions to thwart a comeback attempt by the Red Raiders (12-4, 2-2). She protected the lead by going 5 for 6 from the free-throw line in the final 1:32.
Ellenberg made 7 of 19 shots, including 5 of 10 from 3-point range. She had two blocked shots.
Joanna McFarland added 14 points and 16 rebounds and Nicole Griffin 13 points for the Sooners.
Chynna Brown and Casey Morris scored 11 points apiece for Texas Tech.