Nashua South's Nicole De Jesus puts up a shot during Monday's Division I playoff game against Londonderry. (Photo by Joe Marchilena/NH-HighSchoolSports.com)

LONDONDERRY – There were a few wrinkles Jon Doherty expected to see Monday night when his Londonderry High School girls basketball team hosted a Division I preliminary-round game against Nashua South.

That included seeing a zone defense from the Panthers, and sure enough, that’s what South did to start the game.

While the Lancers struggled a first to adjust, there were other things they were able to do to take control of the game. No. 2 Londonderry suffocated No. 15 South’s offense and scored in transition and on the offensive glass to take a commanding lead on the way to a 73-29 win to start the postseason.

Sammy Sullivan scored a game-high 27 points, including four 3-pointers, and Mia Giampa added 19 points as Londonderry (18-1) got out to a 21-3 lead in the first quarter. Gemma Murray and Brooke Eacrett each chipped in with 11 points as the Lancers topped 70 points for the sixth time this season.

“We have struggled a little bit with 2-3 zones,” Doherty said. “We just don’t see it a lot, so I didn’t have it completely prepped. I kind of figured they’d come out (in a zone).”

But even though Londonderry missed its first four shots, it still jumped out to a 9-0 lead in the first three-plus minutes by forcing three South turnovers and scoring in transition.

“I think we’ve been a defensive-first team, we just happen to have kids that can score,” Doherty said. “Sometimes that defense gets overlooked. With the speed of Brooke and Gemma, and the tenacity of Sam and Regan (Anderson), and Mia stepped up hugely defensively. We don’t lose much defensively off the bench. It’s something I’ve tried to pride us on, but we can fill it up, too.”

South (8-11) got 15 points from Nicole De Jesus and 10 points from Addie Bolden, including two 3-pointers, while Karina O’Donnell finished with four points.

“We’re versing a championship-caliber team that may win it all this year,” South coach John Bourgeois said. “I can’t thank my girls enough for how hard they worked. They fought to the final buzzer and I’m just really happy for the season that they had. All the things they’ve been through, I’m just really proud of them.”

Bourgeois took a timeout after Londonderry went up 9-0, and out of the break, a steal by Nitzann Alkalay led to the Panthers’ first points, a 3-pointer by Bolden that made it 9-3.

But the Lancers answered quick, going on a 12-0 run to take an 18-point lead into the final minute of the quarter. Londonderry led 21-6 at the end of one and stretched the lead to 35-10 at halftime.

“They’re going to get their points in transition and they’re going to get their points on offensive rebounds,” Bourgeois said. “Those are killers for us. It’s hard to stop those things. We can practice that all we want in practice, but we have to execute, and (Monday), it wasn’t our night.”

With the win, Londonderry moves on to the quarterfinals, where it will host No. 7 Salem, which beat No. 10 Alvirne 43-29 in the prelims, on Thursday.