It took a while for Lakeville South to get comfortable Thursday at Xcel Energy Center. Nearly an entire period.

Once they found their comfort zone, the unseeded Cougars went toe-to-toe with St. Thomas Academy, the No. 2 seed, and pulled out a 5-2 victory in the first Class 2A quarterfinal.

St. Thomas Academy (23-5-1) outshot Lakeville South 17-4 in the first period and managed a 1-0 lead on Ray Christy's goal at 8:38. But the Cadets left the ice frustrated after Cougars senior forward Cory Checco's rebound goal tied the score three minutes later.

"The first period is where we could have capitalized and we didn't," St. Thomas co-coach Greg Vannelli said. "When they had their chances, they capitalized on them."

Lakeville South coach A.J. Bucchino acknowledged he was thrilled that the score was tied at that point. "It was a great situation," he said. "It was a two-period game after that."

The Cougars, refreshed and confident heading into the second period, took a 3-1 lead on goals by Jack Olsen and Dawson Klein 47 seconds apart, both the result of improvised faceoff plays. St. Thomas Academy countered with Brenden McFadden's goal 26 seconds after Klein scored, but the Cadets failed to solve goalie Isaiah DiLaura and the Cougars' vaunted defense after that.

"We started off nervous because none of us had been there before," Checco said. "Once we started to get the puck down deep and started checking the way we usually do, we took over."

Lakeville South (19-9-1) added a goal by William Moore and an empty-netter by Bradley Golant in the third period.