Dinwiddie poured in a career-high 21 points and added seven assists while Johnson contributed 19 points and nine rebounds for Colorado (17-7, 7-5 Pac-12).
The victory was the third straight and sixth in seven games for the Buffaloes.
The Wildcats (20-4, 8-4), who lost Sunday to California, got 12 points and seven rebounds from Solomon Hill and 11 points from Mark Lyons.
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