McFarland put together her second consecutive double-double in the process, snatching 16 rebounds as OU won the board battle 38-37.
The Sooners, who struggled to just 34.5 percent shooting in an ugly first half, used a 16-4 run in the opening six minutes and change of the second half to extend a double digit lead at 44-33 that it would never relinquish.
Tech, however, did draw back within as few as four with around four minutes left, but a huge three by Ellenberg gave OU some breathing room once again as it led 55-48.
She scored the final 13 Sooner points of the ball game.
The Sooners eventually outshot Tech 40.4 percent to 37 percent and won the paint battle 26-22.
After losing star senior guard Whitney Hand, the Sooners (14-2, 4-0 Big 12) have now regrouped and since gone 7-1, including their current winning streak.
They'll attempt to keep that going when they hit the road for a 7 p.m. CT date Tuesday evening against Iowa State.