Sophomore guard Grayson Allen scored 33 points and No. 15 Duke overcame a sluggish opening 15 minutes to defeat Long Beach State 103-81 on Wednesday at Cameron Indoor Stadium in Durham, N.C.

Guard Matt Jones had 21 points, guard Derryck Thornton added 18 points and forward Brandon Ingram supplied 14 points for Duke (11-3), which completed the nonconference portion of its schedule.

Allen, who was 15 of 17 on free throws, has reached 30 points three times this season.

Duke has eclipsed 100 points in both games this week.

Guard A.J. Spencer's 20 points and guard Noah Blackwell's 19 points paced Long Beach State (6-9). The 49ers also received 12 points from guard Justin Bibbins and 10 points from guard Nick Faust.

Duke is expected to play at least its first three Atlantic Coast Conference without senior forward Amile Jefferson, who is out with a foot injury.

Long Beach State led for most of the first half, but Duke led 42-36 at the break.

Duke ended the first half on a 13-2 run, with 11 points coming on free throws. Duke was 17 of 18 from the line in the first half.

Long Beach State shot 50 percent from the field (13 of 26) in the first half but was hurt by 14 turnovers. The 49ers had two players foul out before the midway mark of the second half.

Duke has won all three meetings between the schools.