Quinn Cook scored 22 points to help No. 1 seed Duke get off to a torrid start and beat Robert Morris, 85-56, on Friday night in the NCAA tournament's round of 64 at Time Warner Cable Arena in Charlotte, N.C.

Freshman Jahlil Okafor added 21 as the Blue Devils (30-4) wasted little time getting their offense revving, hitting their first seven shots and 12 of 15 to quickly build a big lead.

That's not to say everything went smoothly for Duke, a team with half of its eight scholarship players making their tournament debut in the South Regional. Hall of Fame coach Mike Krzyzewski furiously burned a timeout after Okafor blew a reverse dunk.

Robert Morris (20-15) the No. 16 seed that had to win a First Four game to get here - showed plenty of fight and kept hanging around for the first part of the second half before the Blue Devils finally put the game out of reach.

Duke shot 63 percent in the program's 100th NCAA tournament victory. On Sunday it will play San Diego State.

San Diego State 76, St. John's 64 - JJ O'Brien scored 18 points, Dwayne Polee II added 15 points on five three-pointers, and the eighth-seeded Aztecs (27-8) beat the No. 9 Red Storm (21-12) in Charlotte.

Skylar Spencer added 10 points and seven rebounds for the Aztecs, who never trailed in the second half and improved to 6-4 in NCAA tournament play since 2011 under coach Steve Fisher.

Iowa 83, Davidson 52 - Aaron White scored 13 straight points as part of a 18-3 run early in the second half, and the seventh-seeded Hawkeyes rolled into the South Regional round of 32 by routing the No. 10 Wildcats at KeyArena in Seattle.

White finished with 26 points as Iowa (22-11) used its significant height advantage to overwhelm the champions of the Atlantic Ten Conference regular season.

Mike Gesell added 15 points, and Peter Jok scored 12 for Iowa.

Jack Gibbs and Peyton Aldridge scored 14 to lead Davidson (24-8), but the Wildcats never overcame three early fouls on Tyler Kalinoski, the A-10 player of the year. Kalinoski went the final 35 minutes without scoring, and finished with five points, snapping a string of 21 straight games in double figures.

Iowa was a question entering the tournament after getting knocked out of the Big Ten tournament quarterfinals by Penn State, the 13th-place team in the conference. Any doubt was erased with a strong first half and White's performance in the final 20 minutes.

Gonzaga 86, North Dakota State 76 - Kyle Wiltjer scored 23 points in Seattle to lift the second-seeded Bulldogs over the team that lifts weights in an out-of-commission grocery store.

The Zags (33-2) will play Iowa on Sunday to try to make the second weekend of the NCAA tournament for the first time since 2009.

Dexter Werner had a career-high 22 points for North Dakota State.

The 15th-seeded Bison (23-10), upset winners over Oklahoma as a 12th seed last year, couldn't muster a repeat.