Grayson Allen was in double figures in the first half once again. HALFTIME: Duke 42, Louisville 25 Playing without their leading scorer and biggest interior presence in Marvin Bagley III for the fourth consecutive contest, the Blue Devils continued to rely on Grayson Allen for the bulk of their offensive production in a dominant first half. No. 5 Duke entered the locker room with a 42-25 lead against the Cardinals following another strong shooting performance from Allen and a strong interior showing by its big men. Entering the game with an average of 22.3 points in three contests without Bagley, the Blue Devils' senior captain came out of the gates hot with 13 points on 5-of-11 shooting in the first 20 minutes. After Duke missed its first three shots attempt to start the contest, Allen and Gary Trent Jr. drained back-to back-shots from beyond the arc to give the team an early 10-4 lead, thanks in part to a pair of steals by freshman Trevon Duval. Louisville would take advantage of its interior size, however, relying on 6-foot-11 junior Ray Spalding to cut the Duke lead down to one at 16-15 with 11:14 left in the half. Spalding led the Cardinals with 10 points and six rebounds in the first half. On the other hand, leading scorer Deng Adel has struggled to make an impact, scoring just two points. Even without Bagley, the Blue Devils still have three players taller than 6-foot-11 in the lineup, and they switched to dominate the interior. Duke played through its big men, using putback dunks by Wendell Carter and Javin DeLaurier to spark a 22-6 run that extended the lead to 42-21 with less than two minutes to play. DeLaurier was productive in just his second career start Wednesday, pouring in five points and six rebounds in one of his more productive offensive halves of the season. The Shipman, Va., native also did a good job of staying out of foul trouble, and area where he has struggled, committing just one in 12 minutes. Carter has been the only Blue Devil to join Allen in double figures so far, scoring 10 points. Things to watch in the second half: Duke shot 51.5 percent from the field, but just 37.5 percent from the three-point line. After starting the half 4-for-6 from the field, Allen made only one of his next five shots. Both teams are struggling a bit with turnovers, each committing eight giveaways.