PHILADELPHIA — The phrase “Georgetown in the NCAA tournament” officially became a college basketball punchline Friday night at the Wells Fargo Center, as 15th-seeded Florida Gulf Coast (25-10) blew out the second-seeded Hoyas 78-68. The loss marked the fifth time in six years that Georgetown has fallen to a double-digit seed in the opening weekend of the NCAA tournament.

“There are a lot of things that we have been very good at all year that we were not good at tonight,” Head Coach John Thompson III said. “We didn’t do — as we have for most of this year — [a good job] of making them take tough, difficult shots.”

Georgetown sophomore star and Big East player of the year Otto Porter Jr. struggled from the field in what many have speculated will be his final game as a Hoya. He indicated after the game that he has not yet decided on his plans for next season.

As for Friday, the signs of trouble were there from the start. Senior guard Sherwood Brown and the rest of the Eagles warmed up before the game with an unusual confidence for such a heavy underdog. Still, the outside shooting of Georgetown junior Markel Starks was enough to keep theHoyas in the lead to begin the game.

Then Starks went to the bench with his second foul.

Georgetown subsequently collapsed at both ends of the court, allowing FGCU to close a six-point deficit and eventually take the lead. The Hoyas didn’t make a field goal for nearly eight minutes. Thompson III reinserted Starks with two minutes to play, but it was too late: The Eagles had taken full control.

Georgetown entered the locker room facing a two-point deficit. Most teams can handle that — provided that they don’t allow their opponents to immediately drain a three-pointer and rouse the sleepy crowd with a rim-rattling dunk.

Which, of course, Georgetown did.

“I really felt like we had them right where we wanted them when we went into halftime and we were up by two,” Brown said. “We’re really a team that comes out, second half, with a lot of fire, so that’s when I knew we had them.”

The Blue and Gray made a 6-0 run to briefly tie the game up again, but it wouldn’t last. A sluggish defensive performance against the highly athletic Eagles resulted in several wide-open treys and dunks, and the Hoyas quickly found themselves in a double-digit hole. One play in particular, a highlight-reel alley-oop from point guard Brett Comer to forward Chase Fieler, brought the house down and lifted the Eagles’ spirits to new highs.

“I think it was the highest I’ve ever been,” Fieler said, though his teammates indicated that he had been higher.

In a scenario nobody saw coming, Florida Gulf Coast began stalling on offense to preserve its lead midway through the half. High-energy play on both ends from redshirt sophomore guard Aaron Bowen — and a sudden barrage of three-pointers from Starks, who finished with 23 points — brought the Hoyas back into the game.

“I got a little nervous when those two threes went in in the last two and a half minutes,” FGCU Head Coach Andy Enfield said. “That was about the longest two-and-a-half minutes of my life.”

Thompson III’s squad drew within four points with under two minutes to play, but the Eagles, who had struggled from the line earlier, hit nearly every free throw attempt they were given. Georgetown’s comeback fell short.

“We just didn’t have it today,” Starks said. “What you saw today was not Georgetown basketball.”

Starks was right — tonight’s game didn’t look like the Hoyas of 2012-13. But it did look like the Hoyasof NCAA tournaments past, which prompted questions for Thompson III about the reason for his team’s annual disappointment.

“Trust me, more than anyone on this earth, I’ve tried to analyze it, think about it, look at what we could do — should do — differently,” Thompson III said. “And I don’t know.”