DURHAM, N.C. — Mike Krzyzewski tore off his jacket, he slapped the floor, he gestured toward the crowd — anything to spark his emotionally spent Duke players.
And then his lone scholarship senior got rolling and saved the fourth-ranked Blue Devils.
Quinn Cook scored all 17 of his points in the second half, and Duke beat Georgia Tech 72-66 on Wednesday night to give Krzyzewski his Atlantic Coast Conference-record 423rd league victory.
Justise Winslow added 15 points and fellow freshman Jahlil Okafor had 14 for the Blue Devils (19-3, 6-3), who played for the first time since their win over previously unbeaten Virginia.
"That's a huge win, and now you've got to do it again," Krzyzewski said. "I didn't think we were emotionally at the level we needed to be, no matter what we did. Not that our kids weren't ready to play, but we could not get that level of emotion."
In the second half, Duke never trailed but also never led by more than seven points before finding a way to give their Hall of Fame coach a second milestone in 11 days.
Krzyzewski, who earned his 1,000th career victory Jan. 25 at St. John's, surpassed former North Carolina coach Dean Smith as the winningest in ACC play. He improved to 423-169 in his 35th year in the league.
Chris Bolden scored 16 points and Marcus Georges-Hunt had 14 for the Yellow Jackets (10-12, 1-9). Eight of their ACC losses have come by single digits.
"We've played pretty darned good," coach Brian Gregory said. "We probably deserve a few more wins, and we haven't gotten them. That's what this league is all about right now."
This one also wasn't decided until the final minute. Georgia Tech had the ball down 67-63 after Bolden's jumper in the lane with about 1:15 remaining and Okafor's missed jumper at the other end.
Matt Jones' steal near the sideline set up Cook's two free throws with 33.5 seconds left. Tyus Jones then stole the ball from Demarco Cox and hit Winslow, who was fouled on the break and hit a free throw to put Duke up 70-63 with 23.7 seconds to play.
Tadric Jackson pulled the Yellow Jackets within four with a 3 with 16.8 seconds left, before Cook added two free throws and Winslow blocked Josh Heath's layup with about 5 seconds left.
Jones finished with 11 points for the Blue Devils, whose only double figure lead came late in the first half when Winslow's free throw with 5:13 left made it 33-23.
Cox had 10 points for Georgia Tech, which was 8 of 11 from 3-point range, but its 14 turnovers turned into 20 Duke points.
Okafor had a rough night against a talented Georgia Tech front line. He was just 5 of 12 and missed more shots than he made for just the third time this season, and first time since Nov. 22 against Stanford.
Make it two losses to Duke in less than a week for Ralph Sampson. The former Virginia star and No. 1 draft pick was in the crowd last weekend for the Blue Devils' win over his Cavaliers. He then watched from behind the Georgia Tech bench while his son Robert started at forward for the Yellow Jackets.
Georgia Tech: The Yellow Jackets fell to 5-34 at Cameron Indoor Stadium and their only victory here since 1997 came in 2004 — the year they went on to reach the national title game.
Duke: This was Duke's second game after the dismissal of guard Rasheed Sulaimon, and the Blue Devils were left with just eight scholarship players. Six played at least 22 minutes apiece; Marshall Plumlee played eight while Grayson Allen logged just three.
Georgia Tech: Hosts Wake Forest on Saturday.
Duke: Hosts No. 10 Notre Dame on Saturday.