Kristi Kingma led Washington with 21 points on 7-of-16 shooting, while Aminah Williams added her 12th double-double of the season with 14 points and 12 rebounds.
Washington shot 41 percent for the game, but allowed 51 percent shooting from the Tigers.
Pacific advances to play the winner of Utah and San Diego in the WNIT third round, while Washington finishes the season 21-12. It is the first back-to-back 20-win season for UW since 1993-94 and 1994-95.
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