"We practice them a lot, and normally I do shoot high," Gunderson said. "I shot low and into the corner, and it worked. Initially I was going left, but I changed it up. It's a relief."
Downers Grove North had the better run of play early, but Lyons found its gear midway through the first half.
Late in the half, Eileen Murphy had a long run down the right hashmark and passed to Bella Lestina, but her shot was just high.
Lyons outshot Downers Grove North 10-9 in regulation.
"Once we got through that first 20, with the emotion and adrenaline, I thought we did some great things," Lanspeary said. "We had great opportunities. It was a battle back and forth.
"I love this team, love how hard they play, love how they play for each other. It's been a heck of a season."