BLOOMINGTON, Ind. — Fifth-seeded Oklahoma survived an upset scare from No. 12-seed Florida Gulf Coast in the opening round of the NCAA Tournament on Saturday, hanging on for a wild 73-70 win at Assembly Hall.

Here are three observations.

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OU’s perimeter defense with the game on the line

A 1-for-2 trip to the line left the door open for Florida Gulf Coast to force overtime with 15 seconds left in regulation. But after calling timeout to advance the ball past midcourt, the Eagles shooters were swarmed by white jerseys. It was a brilliant bit of defense by OU, which forced the Eagles to burn valuable seconds as they desperately searched for space before Dolly Cairns attempted a desperation lob that was partially blocked by Skylar Vann with three seconds left.

"We knew what they wanted to get offensively in those last few possessions, so we were like no threes, no fouls, play clean D," Sahara Williams said. "We knew what we had to do and we just really gutted it out, stayed disciplined, executed, and we stayed together and played our game."

The Eagles had three more attempts in the final second, but were unable to convert. Of those chances, the last was the most dangerous with Uju Ezeudu slipping free for an open look from the wing that clanged off the front of the rim and ricocheted off the backboard, before falling off to the side.

Florida Gulf Coast shot 36.7% from 3 with 11 makes, four of which came in the fourth quarter.

"They got a pretty good look, but it didn't go in, so we're happy and we're going to learn from that," Payton Verhulst said.

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Oklahoma’s resiliency and response

There were moments when it felt like the game was on the verge of getting away from the Sooners, be it the inauspicious start to regulation that resulted in a 14-point deficit, or a sudden surge by FGCU in the fourth that swung a six-point lead to a one-point deficit with 90 seconds left.

But at each turn OU managed to mount a response. The wobbly start was followed by significant improvements over the subsequent 10 minutes wherein OU coach Jennie Baranczyk said her players did a better job following the defensive scouting report, while the offense took better care of the ball and began finding its rhythm, clawing back to within a point before the break.

As for the finish, that was simply a matter of absorbing their opponent’s best shot and mounting a response. Aubrey Joens drilled a go-ahead 3-pointer, then Payton Verhulst and Vann broke the 70-all stalemate.

"Florida Gulf Coast led for 32 minutes of the game," Verhulst said. "We talk a lot about wanting to go on the last run towards the end of the game. That's what we did and we closed out the game. We want to start a little bit better going forward, but I think finishing the games is really important in March."

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Verhulst and Joens in the clutch

Beyond Skylar Vann’s 24-point outburst, Verhulst and Joens both delivered clutch performances for the Sooners.

Verhulst accounted for seven of her 14 points in the fourth quarter. She drilled the go-ahead 3-pointer about a minute into the frame, then answered a FGCU layup with a jumper that staked OU to a 72-70 lead with 48 seconds remaining.

As for Joens, she accounted for all five of her points over the final 10 minutes, including the aforementioned go-ahead 3-pointer and a second chance layup that staked the team to a 3-point advantage with 4:39 remaining.

"Aubrey gave us some great energy," Baranczyk said. "She is coming back. Whether or not the ball goes in the hole, that's irrelevant. You can just see her bounce (back) and she provides such a spark for us."

Follow Brian Haenchen on Twitter at @Brian_Haenchen.

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OU vs. Indiana

TIPOFF: 5:30 p.m. Monday at Assembly Hall in Bloomington, Ind. (ESPN2)

This article originally appeared on Indianapolis Star: OU women's basketball edges Florida Gulf Coast in March Madness opener