Collins Hill (20-1) hammered Lassiter (19-1-1) with a constant barrage in the first half, all falling short, but the Eagles were finally able to connect with two goals in the second half to take control of the game.
The Trojans managed to score a goal late in the second half, but couldn't complete the rally.
Not only did the game pit the state's two top-ranked teams - No. 1 Lassiter and No. 2 Collins Hill - against each other, it was a battle of nationally ranked foes. Lassiter was second in the ESPN RISE rankings, followed two spots later by Collins Hill.
"We knew it was going to be a battle," Lassiter coach Billy Pritz said. "We matched up pretty well in all areas. They controlled the midfield for the majority of the game. We made some adjustments at halftime, and the second half was much better for us. We got stretched a little bit there on the first goal, and that kind of slowed down our momentum, and then they got the second and kind of killed off the game.
"The late goal, that was good for dramatics, but we had too many opportunities before that that we should have put away."
Collins Hill will now try for a third consecutive state title Saturday when it hosts Walton, a 3-0 winner over Parkview in the other semifinal.
Collins Hill went on the offensive from the very beginning of Wednesday's game. The Eagles fired a number of shots at Lassiter, but Trojans goalkeeper Jon Stoll was able to keep the ball out of the goal with several big saves.
Lassiter appeared to take the early lead when Bennett Eldredge scored off of a deflection of a free kick by Brandon Barbero with 23:26 remaining in the first half, but the goal was waved off after the Trojans were called for offsides.
"We talked about it at halftime," Pritz said of the negated goal. "You've got to deal with those types of things and don't let these things change the way you play. You've got to adjust to the situation. They disallowed the goal and you have to respond."
After a long shot by Barbero that was grabbed by Collins Hill goalkeeper Jackson Taylor with 17:02 left, the Eagles dominated the rest of the first half with a number of shots of goal.
But Lassiter was able to keep Collins Hill at bay with several saves by Stoll, as well as strong defensive plays from Colton Bryant and Alex Hanks.
Collins Hill began the second half with three scoring attempts on free kicks, two stopped by Stoll and the other going high.
The Eagles were more successful on their next attempt as Eli Carrasco blasted a shot into the Lassiter goal to take a 1-0 lead with 18:40 remaining in the game.
Lassiter managed to contain Collins Hill until the 3:56 mark, when Amiri Abraham scored from close range to give the Eagles a 2-0 advantage.
The Trojans made it a little more interesting at the end when Shaban Abousaud scored to cut Collins Hill's lead to 2-1 with 1:11 left, but by that time, it was too little, too late.
"We came short of what we intended to do, but I'm proud of these guys," Pritz said. "It's a great senior group and it will be tough to replace them. But it will be a lesson the kids will learn and they will get stronger from it."