GREENSBORO, N.C. — Karima Christmas and Jasmine Thomas are used to winning in the Atlantic Coast Conference tournament. Perhaps that's why Duke's seniors seemed so calm late in a tight semifinal game against Georgia Tech on Saturday.

Christmas matched her season-high 20 points to help the eighth-ranked Blue Devils hold off the Yellow Jackets 74-66, sending Duke back to the final for the 10th time in 12 seasons.

Thomas added 12 points for the top-seeded Blue Devils (28-3) as they extended their 17-year dominance over the Yellow Jackets (23-10). They've reached the championship game for the fourth time in as many years under coach Joanne P. McCallie.

Duke beat North Carolina State last season for a sixth championship. The Blue Devils will go for No. 7 against No. 19 North Carolina, which beat Miami 83-57 in the second semifinal.

"It's definitely still exciting for us," Thomas said. "Each year your team is different, and you're playing against teams that also have changed. It's just fun to see how great your team can be."

Christmas reached double figures in scoring for the sixth time in seven ACC tournament games. She also helped Duke maintain its cushion after the Yellow Jackets cut a 13-point deficit to two with about 7 minutes left.

"I think I just have an understanding for when I need to help my team get better, whether it's passing, rebounding or hitting shots," Christmas said. "I was just trying to be aggressive today."

Metra Walthour scored a career-high 20 points and five 3-pointers — including a banked-in runner from just across midcourt to end the first half — to lead the fifth-seeded Yellow Jackets.

Georgia Tech had upset No. 13 Maryland on Friday to reach the semifinals in consecutive years for the first time in program history. But just as last year, the Blue Devils were the ones to send the Yellow Jackets packing for Atlanta.

"We all knew that we didn't want to go home," Georgia Tech senior Alex Montgomery said. "As long as we fought, fought, fought, that's all that was on our mind."

Duke has won 33 straight in the series and hasn't lost to Georgia Tech since February 1994. Most of those wins have come by double-digit margins, including all four previous meetings in the ACC tournament. The closest margin in the past 10 years was a 67-59 Duke win in 2006.

In the only other meeting this year, Duke held Georgia Tech to 29 percent shooting in a 69-32 win. But the Yellow Jackets certainly made the Blue Devils work for this one.

The Blue Devils shot 68 percent (15-for-22) in the opening 20 minutes — their best half of the year and seventh best in program history for a first half — and led 39-29 at the break. But Duke as cooled off in the second half, Georgia Tech kept clawing to get back in the game.

The Yellow Jackets dominated the offensive boards to get 11 second-chance points. Walthour hit her fifth 3, then knocked down three free throws after being fouled on another. Sasha Goodlett scored over Krystal Thomas in the paint to bring the Yellow Jackets within 55-53 with 7:10 to play.

But Christmas rebounded an airball by Thomas to score on a putback that beat the shot clock. Then, after a basket from Haley Peters, Christmas drove past Deja Foster for a left-handed layup that pushed the lead back to 61-53 with 5:06 left.

She also added the press-breaking pass to Krystal Thomas for a layup to answer a Georgia Tech basket.

"I thought Karima was just incredible with her strength," McCallie said. "I thought she made incredible plays to the basket, pretty physical ones with a lot of people hanging on her."

Georgia Tech got within four on three separate occasions, but Duke did just enough to hang on. Thomas hit a key jumper with 1:43 left, then Duke twice forced Tyaunna Marshall (19 points) into turnovers while protecting a 70-66 lead in the final minute. Thomas scored on a layup against the press to punctuate the victory in the final seconds.

"I feel like since we played Duke the first time, we're a different team," Georgia Tech coach MaChelle Joseph said. "I have to give all the credit to my players because they've worked really hard over the last month to be a situation where we got beat by 30 up there and turn around and have a chance to win here a month later."