"I just knocked down shots when they left me open," Hood said. "It was a mental adjustment. We didn't play in the first half like we should have just coming off a loss. Then we came out hungry in the second half."
Guard Quinn Cook's 13 points, forward Jabari Parker's 12 points, guard Rasheed Sulaimon's 11 points and reserve guard Andre Dawkins' 10 points helped Duke (12-3, 1-1 ACC) rebound from Saturday's setback at Notre Dame.
"We had to respond," Cook said of bringing more energy after halftime. "We got the energy that's supposed to be out there after a loss."
"You have to stop the dribble in order to stop the 3s, and we didn't do a good enough job of that," Georgia Tech coach Brian Gregory said of his team's defense.
The Blue Devils shot 57.7 percent (15-for-26) after halftime.
"I think wins in the conference are going to be tough for everybody," Krzyzewski said. "Every one you get you should be thankful for, and we're thankful for that one."
Sulaimon, making his first start since Nov. 24 against Vermont, gave the Blue Devils a boost in both halves.
Duke opened the second half on a 9-2 run and eventually gained a 60-50 lead. Even though Parker, the freshman sensation, was handed his fourth foul with 7:53 to play and didn't return to the game, the Yellow Jackets failed to take advantage.
"We settled too much for jump shots, especially in the second half," Gregory said. "To win on the road, you have to be attacking all the time. That's the challenge. That's why they're good, they challenge you for 40 minutes to make good decisions."
The Yellow Jackets used three 3-point baskets to stick close, and they held a 16-14 rebounding edge at intermission.
NOTES: Duke played its first game without a Top 10 ranking since November 2007. The streak lasted 225 games and covered 122 weekly polls, marking the second-longest run in the Top 10 in NCAA history. ... Georgia Tech G Robert Carter Jr., who was injured last week at Charlotte, underwent surgery Tuesday for a torn meniscus in his left knee. A return to action this season hasn't been ruled out. ... Georgia Tech and Duke had no common opponents on their non-league schedules. ... Duke heads to Clemson next for a Saturday afternoon game. ... Georgia Tech opened the ACC slate with two road games for the eighth time in 35 seasons. .. Georgia Tech plays its ACC home opener Saturday afternoon against Notre Dame. It will be the first of three consecutive home games for the Yellow Jackets.