The Wildcats could not cut into the 20-point plus lead until the 4:25 mark when Megan Mahoney made a lay-up with 4:25 left in the game to make the score 72-53.
The Gophers had the hot hand all night as they made 25 of 48 (52.1%) shots from the field, eight of 15 (53.3%) from three-point range and 22 of 27 (81.5%) from the line.
They held Kansas State to just 22 of 56 (39.3%) shooting from the field and three of 13 (23.1%) from beyond the arc.
Janel McCarville had 15 points and a career-high 18 rebounds. Lindsay Whalen scored 15 points and Shannon Schonrock added 14.
The Gophers got solid contribution from their other two starters, Shannon Bolden (10 points) and Kadidja Andersson (eight), and freshman reserves Jamie Broback (nine points), Kelly Roysland (five) and Liz Podominick (four).
Nicole Ohlde had 23 points and Megan Mahoney scored 17 points for the Wildcats.
Kansas State standouts Kendra Wecker and Laurie Koehn had eight and three points, respectively.
Kansas State fell to 26-5, while the Gophers improved to 23-8.
The Gophers will face Boston College at the Constant Convocation Center in Norfolk, Virginia. The third-seed Eagles (27-6) defeated Ohio State 63-48 Monday to advance. The winner of the Minnesota-Boston College contest will face the winner of Duke-Louisiana Tech.
Gophers coach Pam Borton was an assistant at Boston College for five seasons before Minnesota hired her in 2002.