NORTH ANDOVER — Beneath the bright lights at Merrimack College, St. Mary’s girls flag football team rose to the occasion Thursday. The Spartans (18-0), who haven’t lost a game in three years, completed their quest for a third consecutive Div. 1 state championship with a 12-6 win against Leominster.

Sophia Lafontant was named Most Valuable Player, throwing a pair of touchdown passes and recording an interception on the defensive end.

“It was a really good defensive game,” said St. Mary’s coach Terrell Patterson. “After playing like that, the way the girls competed, I’m just ecstatic.”

St. Mary’s struck first with Kaileigh Patterson finding the promised land on a corner route.

“It really set the tone and delivered that big punch that I don’t think Leominster was expecting,” Terrell Patterson said of his daughter’s tally.

Leominster tied the game, 6-6, and threatened later in the game, but the Spartans forced a massive turnover on downs.

Eleni Echevarria hauled in the go-ahead touchdown to make it 12-6. In crunch time, with Leominster making its final push, Lafontant broke up a fourth-down pass to give St. Mary’s its three-peat.

“She (Lafontant) is a great quarterback — one of the best around — but also a terrific defensive player,” Terrell Patteron said. “This is a really young team. Sophia is just finishing up her sophomore year, Kaileigh just finished eighth grade, and Eleni is a freshman. We have no juniors or seniors.”

Earlier Thursday evening, the Spartans defeated Wachusett, 25-0, in the semifinals.