Keisei Tominaga led NU with 15 points, but St. John's used a pair of decisive runs early in the second half to post a 70-50 victory in the Gavitt Tipoff Games.
Tominaga hit 5-of-8 shots, including 3-of-6 3-pointers, but the Huskers shot just 29.7 percent from the field and committed 17 turnovers that led to 21 Red Storm points.
David Jones scored all 15 of his points in the second half for St. John's (4-0), while Joel Soriano (17 points, 18 rebounds) and Posh Alexander also finished in double figures for the winners.
Nebraska led 27-20 at the break, but St.