That lack of fire power coupled with the stellar effort of Maryland point guard John Gilchrist helped erase a nine point Duke lead and gave the Terrapins a chance to win in regulation, but Nik Caner-Medley's attempt at the buzzer rimmed out.
The extra period meant little as the absence of Williams and Ewing had already sealed Duke's fate. Both tallied 23 points, with Williams adding 16 rebounds before being seated with his fifth foul.
Fellow junior J.J. Redick added 21 for the Blue Devils, who now find themselves on the outside looking in for a shot at the ACC Regular Season title with a conference mark of 8-3.
After trailing by five at half time, Duke quickly started the second period with a 9-2 spurt to take a 52-50 advantage. Soon after Williams began to take over inside, scoring a pair of baskets to spark another Blue Devil run to build a 71-63 lead.
Then things began to take a turn for the worse for head coach Mike Krzyzewski and company as Ewing was retailiated after being caught with an elbow by Ekene Ibekwe. The junior was whistled for a technical foul that sent sophomore Mike Jones to the line. Jones would convert one of two, and then score seven more points in a three minute span to tie the game at 73.
Duke would rebound and take a four point lead with 1:34 remaining but a pair of three point plays by Maryland would spell the end of the night for Williams and Melchionni and give the capacity crowd something to cheer about.
The Blue Devils got a DeMarcus Nelson basket to tie the game with just under 30 seconds remaining, setting up the final series which culminated in Caner-Medley's miss at the buzzer.
The victory gives Maryland their first sweep of Duke since the 1995 season, while extending their win streak to three over the Blue Devils dating back to last year, the first time that program has accomplished that since the early 1980s.
With the loss, Duke heads to Virginia Tech on Thursday looking to stay within striking distance of Wake Forest's 9-2 ACC pace.