Mount Saint Joseph boys basketball is the No. 1 ranked team in the Baltimore area and two-time defending Maryland Interscholastic Athletic Association A Conference champions.

Archbishop Spalding is a young team showing plenty of promise but still finding its way.

The teams played their expected roles in Thursday night’s conference semifinals, as the senior-laden Gaels came out fast while the Cavaliers showed early jitters. The fast start and balanced performance — Austin Abrams led four players in double figures with 18 points — sent Mount Saint Joseph to the championship game with a 70-56 win over Spalding.

The Gaels improved to 35-3 and will take on No. 4 St. Frances — an 89-84 winner over No. 7 Mount Carmel in Thursday’s other semifinal — at 5 p.m. Sunday at UMBC’s Chesapeake Employers Insurance Arena.

In winning their 20th straight game, the Gaels took control from the start. Senior Ace Valentine scored nine of his 17 points in the first quarter, with his 3-pointer with 21 seconds left in the frame providing an 18-4 lead.

“We just wanted to come out and play fast, have a lot of energy and keep the momentum up from our winning record,” Abrams said.

The Gaels kept pressing in the second quarter, getting a 3-pointer from DJ Wingfield to take their biggest lead at 27-6.

Spalding, which started two juniors, two freshmen and a sophomore, kept working hard and shot better as the game went on. A three-point play from RJ Newton cut the Gaels’ advantage to 62-49 with 2:46 to play.

Sophomore wing Malik Washington finished with 14 points for Spalding, while Newton reached double figures with 10. The Cavaliers, who claimed a 76-58 win at John Carroll in Tuesday’s quarterfinals, will take a 14-17 record into next week’s Baltimore Catholic League tournament.

Coach Josh Pratt is impressed with his young team’s growth over the course of the season — particularly during Thursday’s challenging playoff assignment against the defending champions.

“We got a young team, so playoffs, semifinals — if we get some of those shots early, maybe it’s a different ballgame,” he said. “But we didn’t put our heads down and all those things, and it is what it is. Congratulations to them. We just got to get better.”

Mount Saint Joseph will look to add another trophy Sunday against St. Frances, it’s fiercest rival in recent years. The Gaels claimed both regular-season meetings against the Panthers — a 62-59 road win Jan. 6 and an 82-64 home victory Feb. 12.

“It’s going to take heart, effort and we got to give it everything we got. Championship game for the MIAA, so we got to leave everything on the line,” Valentine said. “We’re a 20-game win streak, so we got all the confidence in the world. But we got to step up and do what we need to do, do what we’ve been doing to get this win.”

Mount Saint Joseph coach Pat Clatchey was not surprised to hear that St. Frances will be Sunday’s opponent.

“We played them twice already and they’re a good team, very talented and we’re going to play a good game to beat them,” he said. “We’ve had a great season, [Baltimore Catholic League] regular-season champs and this is our 35th win. But I told my guys that people remember what you do at the end of the year.”

No. 4 St. Frances 89, No. 7 Mount Carmel 84: The Panthers leaned on their biggest stars to get past the Cougars.

Senior Carlton Carrington led the way with a game-high 31 points, Tyler Jackson added 21 and Jahnathan Lamothe scored 18 as the Panthers rallied from a 42-41 halftime deficit. St. Frances went 18 of 20 from the free-throw line to help seal the win.

For Mount Carmel, junior Drew Dixon scored a team-high 23 points and Mario Tatum added 17.

B Conference

Chapelgate Christian 63, St. Paul’s 57: Chapelgate Christian has been to the MIAA B Conference semifinals before. But since joining in 2011, that’s as far as it has gotten.

Alumni like to debate which is the greatest Yellow Jackets team of all time. With several of them in attendance at Thursday night’s semifinal, coach Frick Frierson told his players they had an opportunity to set themselves apart in that conversation.

After trailing by eight at halftime, the Yellow Jackets completely flipped the game in the third quarter by ratcheting up the intensity level. No. 2 seed Chapelgate outscored No. 6 St. Paul’s 18-5 in the third quarter in the 63-57 victory. Chapelgate will face top seed St. Mary’s in Sunday’s championship game.

“During the first half when they got that lead, we were starting to get frustrated with ourselves,” senior guard Jaylen Marbley said. “Once we got into the locker room, we talked it out, started to bond together. We said, ‘We’re going to win this game,’ and we were all determined to. So we all focused together and made one goal happen to win the game.”

— Jacob Steinberg

St. Mary’s 55, Archbishop Curley 47: “One more,” the St. Mary’s boys screamed when it was done.

It wasn’t easy to quell Archbishop Curley on Thursday night, but the Saints were dominant when they needed to be to win the MIAA B Conference semifinal, 55-47.

“The championship run is going to be hard no matter what. At least we have guys who have experienced it before,” Saints coach Trey Quinn said. “The pressure of win or you’re done. And I think it showed with our seniors tonight: they were ready to go.”

Yes, St. Mary’s (23-7) is going back to the B Conference final, looking for its second straight title, but the circumstances are different this year. Last year’s squad concluded years of work and ascension to reach that finale. This year’s team weathered heavy graduation losses but regrouped to be something special again.

“It feels a little different because it’s a whole new squad,” senior Jaden Bryant said. “But we’re still doing the same things as last year. I’m just proud to achieve this with these guys.”

Understandably, there were plenty of St. Mary’s games this year in which only one or two players really stood out. That was not the case Thursday. Senior Aidan Harris led with 22 points, while fellow seniors Casey Smith (nine), Bryant (eight), Ajani Lomax (six) and Grady Wolfe (six) chipped in.

Everyone, in the third quarter especially, made his mark on a key basket — or many. Everyone pulled that necessary rebound, made that block, forced that turnover, gave that assist or guarded that Friar.

“You always want to be hot at the right time,” Quinn said. “Part of that was game plan. They play phenomenal help defense, so we knew, ‘OK, the [Curley] guy that starts with the ball is not going to be the one that finishes.’ Our guys embraced that. Really had some good looks to get guys open shots.”

— Katherine Fominykh