All season, missed free throws have proved costly for No. 13 Georgetown. On Thursday, a handful of misfires late — and their inability to stop Cincinnati forward Yancy Gates in the clutch — halted the Hoyas’ run in the Big East tournament.

Gates scored 15 of his game-high 23 points in the final six minutes of regulation and extra time, and Georgetown missed all but one of its final six free throws in a 72-70 double-overtime loss in the quarterfinals at Madison Square Garden.

Making the defeat sting more: Georgetown owned an 11-point lead with 9 minutes 11 seconds remaining in regulation. The Hoyas also wasted a career afternoon for senior Henry Sims, who followed Wednesday’s double-double with a 22-point, 15-rebound effort against Cincinnati.

“It was a battle, a battle, but late in the game we just weren’t able to hold tight,” sophomore point guard Markel Starks said. “They wound up hitting a big shot.”

With the game knotted at 70, Cincinnati guard Cashmere Wright raced past Jason Clark to the hoop and scored the decisive basket with 7.6 seconds left in the second overtime. At the other end, Sims’s desperation three-pointer clanked off the rim as time expired.

“It was all set up by Yancy,” Wright said. “When he ducked in, it seemed like the whole team sucked into him. So the hole just opened up wide and I took it upon myself to win the game for my team.”

A little after the midway point of the second half, the fifth-seeded Hoyas (23-8) were ahead 49-38 and seemed to be closing in on a semifinal meeting with top-seeded Syracuse on Friday night.

That, however, is about the time Gates — a considerable load at 6 feet 9, 260 pounds — took matters into his own hands. He scored 10 of the fourth-seeded Bearcats’ final 16 points as they rallied to force overtime.

“Yancy is tough every night,” Coach John Thompson III said. “Yancy hurt us, not just with the post moves, but he got some big second shots [where] we needed to get the defensive rebounds.”

It was as much Gates as it was the Hoyas. In the final eight minutes of regulation, they went 1 for 4 from the free throw line. Two of those misses were the front of one-and-one opportunities, both by Starks.

“It was a big free throw that probably would have sealed the game,” said Starks, referring to his miss with the Hoyas leading 52-49 with 2:08 remaining in regulation. “On this one, I kind of put it on my shoulders.”

In all, the Hoyas shot 8 for 15 from the free throw line. They’re tied for seventh in the conference at 69.7 percent.

“The key things were rebounds, turnovers and to put your foul shots in,” said Thompson, whose team committed 12 of its 14 turnovers in the second half and extra time. “That’s the difference.”

Sims was the difference in the first overtime. The 6-10 center evened the score at 62 on a determined drive to the rim as the clock ran out. Earlier in the period, though, Sims missed two free throws. In the second overtime, Sims scored a leaner with 28 seconds left to tie the score at 70.

Wright made sure it wasn’t enough.

“He’s a good player who made a good read,” said Clark, who has 12 points and was guarding Wright. “Our defense was kind of spread. He got into the lane and made a good play.”

After Wright’s driving layup off the glass, Cincinnati Coach Mick Cronin called a timeout with 7.6 seconds remaining, leaving the Hoyas plenty of time.

But Clark was headed off by Wright at the arc. With few options, Clark passed the ball to Sims, who launched a low percentage shot from the top over JaQuon Parker.

“Jason . . . threw it to Henry for a wide-open shot,” Thompson said. “The ball didn’t go in.”

In a game that produced its share of plot twists and intriguing statistics, one of the more interesting numbers had to be the Bearcats’ performance from three-point range.

“To go 2 for 21 from three against Georgetown and win the game is unthinkable, to be honest with you,” Cronin said. “It’s just unthinkable that we were able to dig it out.”