BIRMINGHAM, Ala. — Maryland and South Carolina played an instant classic. There were no butts in any seats for the final 90 seconds — standing room only in downtown Alabama.

It would’ve been hard to fathom just a few hours before tip-off that it could be this close. No. 4 seed Maryland jogged onto the court met by some light shouts, then No. 1 South Carolina stormed in behind massive flags while deafening roars filled Legacy Arena. That alone felt indicative of the delta in program grandeur.

Even if the defending champions and heavy favorites edged out a 71-67 win, it never felt that way between the lines. Neither side could string together enough plays to pull away.

Maryland had its chance late. The Terps were down four with 20 seconds left, enough time to turn their luck. Shyanne Sellers inbounded the ball to Sarah Te-Biasu, who tried to give it back. They fumbled the handoff, and the ball squirted out of bounds, giving the Gamecocks possession. Four more South Carolina free throws decided it.

These are two teams from different tiers of college basketball. The Gamecocks (33-3) capped last year’s undefeated season with a national championship. This year’s group is chock-full of McDonald’s All Americans with a deep bench under the direction of Hall of Fame coach Dawn Staley. Some might go as far as to say it’s a women’s basketball school.

Maryland (25-8), on the other hand, has been relentless this tournament in fighting from behind and finding ways to win. Friday was, from the outsiders’ perspective at least, expected to be the end of the line. The Terps were 17-point underdogs.

But this is March, home of the quirky and unexpected, when teams regularly punch above their weight class with unbridled confidence.

The Terps fearlessly threw jabs with their season on the line. Knowing the importance of the rebounding battle in this one, they were methodical in defending the rim and especially adept at tracking the ball on its way down. It had them on top by two at halftime, 33-31, then down by only two after three quarters, 52-50.

What Maryland did best to keep this game close was make South Carolina pay for every mistake.

When the Gamecocks weren’t all the way back on defense, Maryland shoved the ball up the floor in transition, often for a bucket or at least a foul on the way up.

A travel or errant pass by South Carolina led to a Maryland possession that, in a way, seemed as if the Terps were more aggressive. By game’s end, Maryland totaled 18 points off turnovers, compared with South Carolina’s seven.

The crowd slowly inched forward in their chairs.

There weren’t too many confident in predicting a battle this close.

South Carolina controlled the glass, a battle both said would be a focal point. The Gamecocks dominated in that department, 47-34.

Kaylene Smikle was judicious in keeping her team alive. She scored an unrelenting 17 points, playing much of the game on a hurt ankle. Allie Kubek, who fouled out with about three minutes remaining, was a bully on the block, scoring 12 points to go with five boards. Te-Biasu had 12 points and Sellers added 10.

South Carolina’s winning effort came thanks to 23 points and five rebounds from MiLaysia Fulwiley. Chloe Kitts scored the Gamecocks’ first 10 points but was hushed to only five the rest of the way. One of those was a free throw that put South Carolina up 62-60 with 1:47 left, followed by a layup from Fulwiley. Two more free throws by Kitts gave the Gamecocks a 66-60 lead with 34 seconds to go.

At times this year, Maryland has had internal conversations about a friend inside the locker room. The kind that can be as helpful as she is dejecting. Coach Brenda Frese waxes eloquently as if this basketball construct is in the room with them, living and breathing to help them win games.

Her name is “Mo” — short for momentum — and the Terps can’t win without her on their side. She was wearing red and gold for much of Friday’s Sweet 16 matchup, until she sprinted over to South Carolina’s side in the waning minutes, backed by a crowd in maroon.

After starting in the passenger’s seat, the Terps made four quarters worth of plays that put the defending champs on upset watch. South Carolina hasn’t lost a tournament game preceding the Final Four or national championship in 2,191 days. The Gamecocks are now 19-1 in the past four NCAA Tournaments.

Maryland fell just short of making history.

Have a news tip? Contact Sam Cohn at scohn@baltsun.com, 410-332-6200 and x.com/samdcohn.