DURHAM, N.C. _ Through Duke's first nine games, it had been a second-half team _ susceptible to slow starts that would ultimately end in big finishes.
When it played Indiana at Assembly Hall in Bloomington on Wednesday, No. 1 Duke trailed by four points with five minutes left in the game. And during its three games in the PK80 tournament, it trailed at halftime of each game, before coming from behind to win.
But on Saturday, Duke dominated in the first half and did not play well in the second.
This time, however, its first half was so good, whatever happened the rest of the way really didn't matter, and Duke won 96-80 over South Dakota.
Duke (10-0), which led 56-30 at halftime, will play one more nonconference game on Tuesday against St. Francis (Pa.) before it plays its first conference opponent, Boston College, next week.
Senior Grayson Allen was one of the primary reasons Duke was so good early on. Prior to Wednesday's game against Indiana, in which he scored 21 points, the 6-5, 205-pound guard had gone cold in the five games since his 37-point performance against then-No. 2 Michigan State.
But he scored 15 points (6-for-8 shooting) in the first nine minutes of the game on Saturday. At that point, Allen had outscored South Dakota (7-3), which had only 13 points. Allen finished the game with 25 points (8 for 11).
Freshman forward Marvin Bagley III had 19 points and 12 rebounds. Freshman point guard Trevon Duval added 14 points and eight assists.
Coming into Saturday's game, South Dakota ranked 23rd in the country in field-goal percentage defense, allowing just 37 percent of its opponents' shots. But it also hadn't played any top-ranked teams.
By halftime, the Blue Devils led the Coyotes in nearly every statistical category. They outrebounded the Coyotes, 26-13, outshot them 62 to 37 percent and dominated in second-chance points, 14-0.
After a day off, following their fourth game in seven days, the Blue Devils focused on defense in practice. Defending points in the paint from easy baskets in transition had been a problem. And through the games first 20 minutes, the Blue Devils had that under control (36-14).
But the second half started rough. Duke turned the ball over 14 times after halftime. At one point after giving up a turnover and an easy bucket, Duke coach Mike Krzyzewski called a timeout. When he stood up from the bench he clapped his hands in frustration.
South Dakota outscored Duke 50-40 in the second half.
Despite Duke's second half, though, its first half was too good.
