GREENSBORO, North Carolina (Ticker) -- Shelden Williams scored a career-high 27 points as No. 4 Duke began a quest for an unprecedented sixth straight Atlantic Coast Conference tournament title with an 84-74 win over Virginia.

Daniel Ewing scored 18 of his season-high 26 points in the first half as Duke (25-4) took a 46-40 lead that it never relinquished. The Blue Devils have won a league-record 16 straight ACC tournament games.

Ewing, the the tournament's Most Valuable Player as a sophomore last season, made 8-of-14 shots before fouling out with 1:35 remaining.

"I can't really say what it is about the first round of the ACC tournament," Ewing said. "It was one of those situations that was similar to last year. We were struggling and I was able to make some big plays for us in the first half."

The Blue Devils will face Georgia Tech in the semifinals.

J.R. Reynolds scored 20 points and Elton Brown added 14 for Virginia (17-12), which likely is headed to the NIT.

"I'm very proud of our team," Virginia coach Pete Gillen said. "We played a great team in Duke. With 2 1/2 minutes to go we were down five, we had a chance to possibly steal the game. We just didn't make enough plays. We just couldn't get enough stops."

Williams scored 18 points in the second half, when he made 4-of-5 shots from the floor. Duke led by as many as 14 points in the final 20 minutes.

"Daniel carried us in the first half and Shelden carried us in the second half," Duke coach Mike Krzyzewski said. "Those were two magnificient performances."

The Blue Devils shot 50 percent (25-of-50) and turned in a strong defensive performance with 11 blocked shots and 11 steals.

The Cavaliers got no closer than five points in the second half, with the final time coming, when Todd Billet hit a pair of free throws to make it 75-70 with 1:35 to play. Billet missed all five of his shots from the floor.

J.J. Redick made two from the line two seconds after Billet converted a pair, and on Virginia's next possession freshman Luol Deng swatted Billet's attempted layup. The Blue Devils closed the game by making 7-of-8 free throws.