Trailing by as many as 11 points, the visiting Knights rode the hot-hand of Bailey Cooke in the second half, taking the lead at various stages, before eventually succumbing to the Lancers, 40-39.
Keegan Anderson converted from the foul-line to finish off a three-point play with under a minute remaining, lifting Lasalle past the hard-charging Knights.
It marked the fourth change of the lead in the fourth quarter alone as Cooke scored all 18 of her points in the contest over the final two quarters, with Lasalle focusing completely on shutting down Lo-Ellen scoring machine Marianne Alarie.
For their part, the homeside featured a more balanced offensive approach, with veteran Lindsay Scruton leading the way with 20 points, while Karli Marcotte and Kristen Ferguson also contributed with key baskets down the stretch.
Staring down a deficit of 31-21 midway through the third quarter, Cooke drained a three-point shot, kicking off a run where she would score 14 of her team's final 18 points.
"Number eleven (Cooke) had a great second half for them, she really came to play," said Lasalle head coach Mitch Lalonde. 3
"Probably half the games we've won this year have been just like this one," he continued. "Our girls just find a way to pull it off at the end — they know how to win."
Still, for a relatively young team overall, there was a little extra incentive.
"We felt that we needed to win it for the seniors," said Karli Marcotte, one of a bulk of young Lancer stars who will be returning next season.
The youthful enthusiasm that can often key the strength of the frenetic pace Lasalle can play at both ends of the court can provide a double-edged sword with the drama of playoff action at hand.
"My mind was racing," Marcotte said. "It's crazy. You really have to focus, to put all of your might into it."
With a trip to the city final on Saturday now safely secured, the Lancers will focus on the key elements that played a big part in the regular season success the team enjoyed.
"We need to play good defense, and slow down our offense, finishing when we need to," Marcotte said.
It will be a match-up of the top two teams in the championship affair, as the Lockerby Vikings took care of business at the other end of town, bouncing the Notre-Dame Alouettes 49-34 in the remaining semifinal encounter.
The Vikings held the advantage over the past two months, beating the Lancers in two of their three regular season games, though the margin of victory averaged just two points.
The senior final will cap off a full afternoon of basketball at Lasalle on Saturday, with the midget final slated for noon, the juniors at 2 p.m. and the Lasalle-Lockerby tilt at 4 p.m.