"We had a really tough time, and it looked like we were ill-prepared, and that's squarely on my shoulders," said Mitchell, whose team had defeated Baylor earlier this season in a memorable 133-130, four-overtime game.
The Cats have been able to overcome cold-shooting games this season thanks in large part to their aggressive defense, but were only able to force eight turnovers against Baylor. It marked the first time in the last 187 games that UK has not forced double-figure turnovers.
Baylor led 49-32 at the half and was never threatened after the break. The closest UK could draw was 12 points.
The Lady Bears (32-4) got a game-high 25 points from national player of the year candidate Odyssey Sims. Nina Davis followed with 20 points and eight rebounds, while Khadijiah Cave added a career-high 18 points and nine rebounds.
The Wildcats have reached unprecedented success under Mitchell, advancing to the Elite Eight in three of the past four seasons, but have not been able to break through to the Final Four.
"We've played really good teams, and we've dared to develop the program to a point to get them in games like this," Mitchell said. "It's disappointing to perform like this in this type of atmosphere."