Tyus Jones had 16 points and a season-high 10 assists, and No. 4 Duke beat Army 93-73 on Sunday to bring coach Mike Krzyzewski within 10 wins of 1,000 for his career.
Fellow freshman Jahlil Okafor added 21 points while Quinn Cook and Rasheed Sulaimon had 13 apiece for the Blue Devils (7-0).
They shot 52 percent, held a 43-25 rebounding advantage and overcame a season-worst 4-of-19 performance from 3-point range.
Duke tuned up for Wednesday night's visit to No. 2 Wisconsin by helping Krzyzewski defeat his alma mater and earn career victory No. 990.
Kyle Wilson and Tanner Plomb each scored 19 points for Army (5-1).
The Black Knights gave Duke's transition defense headaches all day before their best start in 38 years was spoiled by its former team captain and head coach.