Kyle Singler scored 14 and Ryan Kelly added 11 as Duke leads Maryland 42-33 at the half.
Singler and Kelly each made all five of their field goal attempts.
Nolan Smith, Duke's leading scorer, was held to just two points in the first half and had four turnovers.
Jordan Williams posted 10 points and seven rebounds for the Terrapins.
Both teams shot over 50 percent from the field.