Sims hit a pair of free throws and then got a steal in the backcourt for a layup that got Baylor back within a dozen, and the Lady Bears put together a 19-4 run to get within striking distance in the final 2 minutes.
Baylor scored 17 points off the Lady Raiders' 13 turnovers, while the Lady Bears coughed up the ball eight times and Texas Tech got 10 points from them.
Baylor had a series of uncharacteristic turnovers that fueled a furious late charge by Oklahoma State, but the Lady Bears never trailed in a 77-69 victory Sunday in the Big 12 tournament semifinals.
Last year, they lost to Baylor in Lubbock by eight points and in Waco by five, by far the narrowest victory margins during the Lady Bears' 40-0 season.