Northeastern forward Scott Eatherton, left, drives against Georgetown's Mikael Hopkins. (Ricardo Arduengo/AP)

Georgetown had every possible physical advantage Thursday against Northeastern in its opening game of the Puerto Rico Tip-off.

Northeastern’s most imposing starter was 6 feet 8 and 219 pounds; the Hoyas could field an entire starting lineup with athletes 6-9 or taller.

But heart had far more to do with the outcome than heft. On that count, the Hoyas came up woefully short, letting a 14-point, second-half lead evaporate during a stone-cold stretch in which they got outmuscled in the paint, whiffed on free throws and tossed up rash three-pointers en route to a 63-56 defeat.

It wasn’t just that Georgetown’s shots refused to fall when it mattered most. It was the utter lack of intensity and fundamental game-smarts that told the baffling story of the Hoyas’ first regular season loss to a current Colonial Athletic Association team since 1968-69, when William and Mary pulled off the shocker.

Despite its prodigious size advantage, Georgetown was outscored in the paint 34-26 and lost the rebounding battle 36-32.

Traditionally stout on defense, the Hoyas allowed the foul-depleted Huskies to blow past them time and again for easy baskets down the stretch. Northeastern shot 52 percent in the second half, while Georgetown made only 23 percent of its shots — and went 0 for 8 from three-point range.

The turnabout was so dramatic after Georgetown had taken an 11-point halftime lead that it defied traditional analysis, in the view of Coach John Thompson III.

“This group quickly, quickly needs to figure out how to compete,” said Thompson, who never hit on a lineup with the moxie to stage a comeback against a team it had ample opportunity to put away in the first half. “We can sit and talk offensive systems, defensive systems, rotations, slides and everything. We have to compete. I thought we did a poor job of rolling up your sleeves and competing.”

Sophomore guard D’Vauntes Smith-Rivera was the only Hoyas player to manage double figures, finishing with 14 points on 5-for-14 shooting. His back-court mate, Markel Starks, shot 2 for 12 from the field (including 1 for 7 from three-point range) to finish with nine points.

Smith-Rivera’s analysis echoed his coach’s.

“I give them credit for the defense they played,” Smith-Rivera said, “but at the same time I feel like we didn’t attack in our offense like we needed to. We were taking unnecessary shots early in the shot clock.”

The loss relegates Georgetown (1-2) to the loser’s bracket for Friday’s second-round games, in which the Hoyas will face Kansas State, upended by Charlotte, 68-61, earlier Thursday.

Admittedly starstruck at the outset, Northeastern (2-2) could do little right in the early-going, turning the ball over, rushing the pace and fouling repeatedly to help Georgetown to an 11-3 lead.

The Huskies did well to stay within six of the Hoyas for most of the first half, driving for high-percentage shots, holding their own on the boards and defending well.

Smith-Rivera hit a three-pointer with 4:22 remaining in the period to extend the Hoyas’s lead to 30-21. And with a terrific dunk by Aaron Bowen, Georgetown took a 36-25 advantage at the break.

Northeastern’s challenge got more daunting when its best three-point shooter, Demetrius Pollard, fouled out with more than 17 minutes remaining. Soon after, leading scorer and rebounder Scott Eatherton picked up his fourth foul.

But the Huskies made a critical adjustment, abandoning the perimeter game for the most part and taking the fight right to Georgetown’s post players.

Northeastern didn’t attempt a three-pointer in the second half, opting instead to slash to the basket, where a succession of Hoyas big men — 6-10 Joshua Smith (nine points, six rebounds), 6-9 Mikael Hopkins (five points, six rebounds) and 6-8 Nate Lubick (six points, six rebounds) — mounted scant resistance.

For Northeastern Coach Bill Coen, the strategic epiphany came in studying the first-half statistics, which showed Georgetown scoring 26 of its 36 points on second-chance points and turnovers. From then on, he told his Huskies to eliminate the turnovers and pound the boards — guards included.

“We can’t match them athlete for athlete,” Coen said. “We have to take care of the basketball and take those easy baskets off the table.”