Charles Nailen/The Hoya Freshman guard Matt Causey struggles as he is smothered by opposing defenders during Saturday’s game against Duke at MCI Center.

It was a game for about 13 minutes. Then it rapidly escalated into a blowout, ending with Duke’s 85-66 win over Georgetown.

The Blue Devils (16-1, 5-0) went on a 30-8 run at the end of the first half Saturday, shutting down the Hoyas’ offense and showing with what ease they could hand Georgetown (11-4, 2-3) its second loss to a No. 1 team in 10 days.

The tandem of sophomore forward Shelden Williams and senior guard Chris Duhon proved unstoppable, scoring almost an effortless 26 and 17 points each. It was a career high for Williams.

“I thought [Williams and Duhon] were the keys to the game,” Head Coach Craig Esherick said. “And after that the game was over. That game was over early.”

In what was surely the most hyped game the Hoyas have played in years, students turned out in droves with face-paint and costumes for the nationally televised matchup, and signs even hung out of dorm room windows on campus on Saturday morning. But the crowd of 20,193 was deflated by halftime, and toward the end of the game a “Fire Esherick” chant could be heard coming from the stands.

Yet the excitement that comes with facing the top-ranked team in the country, combined with Georgetown’s first ever sellout crowd at MCI Center, may have provided the spark that kept Georgetown in the game for the first 13 minutes or so, when the score was only 16-18.

“They knocked us back early with the energy that they had,” Duke Head Coach Mike Krzyzewski said.

But Williams was just getting started. As the game went on, he exploited what has been a Georgetown weakness all season: the lack of an inside defensive presence. In the first half, senior center Courtland Freeman seemed to back off of the dunks and layups that Williams and freshman forward Luol Deng were getting with ease. But his avoidance did not pay off, as he later ended up fouling out midway through the second half.

“Williams was very effective down in the low post the entire game,” Esherick said, “and we had no answer for him; absolutely none.”

Freeman, who on Tuesday had a double-double and scored the game-winning basket, was not a factor on Saturday. He was 1-for-2 and did not grab a single rebound in 19 minutes. His replacement, freshman forward Amadou Kilkenny-Diaw was also ineffective, with much the same line.

“Once you get past Freeman, they have youth inside,” Krzyzewski said. “And Freeman has to play a certain way so he stays out of foul trouble, so we knew we had an advantage there.”

In addition to the Hoyas’ poor defense, the vision of Duhon was another reason why Williams got so many opportunities. Duhon passed the ball inside more or less flawlessly, leading the team with five assists.

And although Duhon is known for his drives to the basket, he adapted to a Georgetown defense that allowed him the outside shot. Duke shot 43.8 percent from the three-point line, including Duhon’s 3-for-5 mark.

Duhon and Williams both relied on Duke’s most powerful weapons of the day: inside shots and three-pointers. Of Duke’s 35 field goals, 27 came in the paint and seven were three-pointers, leaving just one that was in between the paint and three-point line.

Leading Georgetown in scoring and rebounds were sophomore forward Brandon Bowman, who had 19 points and nine rebounds, and sophomore guard Ashanti Cook, who had 13 points and eight boards. Junior swingman Darrel Owens led Georgetown in the first half with 10 points on 4-for-6 shooting, including two three-pointers, but did not score again.

With the victory, Duke extended its winning streak to 13 games while Georgetown has lost four out of its last five.