Ethan Wragge added 16 points and nine rebounds, and Jahenns Manigat had 10 points for the Bluejays (7-2), who unveiled gray uniforms for the annual meeting with their in-state rival from 50 miles away in Lincoln.
The game turned chippy with just more than a minute left with Creighton's Grant Gibbs and Petteway getting ejected for trading blows during a scuffle for a loose ball.
The Bluejays won by double digits for the third straight year. This one got out of hand early in front of the pro-Bluejays crowd of 17,530 at CenturyLink Center. McDermott scored 11 points in the first five minutes as Creighton broke out to an 18-2 lead, and the Bluejays were up 32 points late in the half. Creighton made seven 3-pointers and shot 55 percent in the first half. McDermott had three 3s in the first five minutes and 17 points in the half.
Nebraska opened the game with misses on 10 of 11 shots. The Huskers were 1 of 12 from beyond the arc in the first half and went into the break shooting 30 percent.
The Bluejays carried over their momentum to the second half with McDermott scoring six straight points, including a dunk off Gibbs' pass.
Petteway gave the Huskers a little spark. He made a 3-pointer and dunked after stealing the ball from Austin Chatman to cut it to 59-37. Wragge's back-to-back 3s restored Creighton's 30-point lead, but Nebraska kept playing hard.
The Huskers pulled to 19 points for the first time since the middle of the first half with Petteway dunking in transition to finish an 11-0 spurt. McDermott made two straight 3s, but after back-to-back dunks by Walter Pitchford and Shields, Nebraska coach Tim Miles called timeout to set up the press with his team within 75-57.
The Huskers never got closer than 15 the rest of the way, though.