He battled some foul trouble and sat much of the third quarter, but for a guy that young to not only start, but impact the game as much as he did, it's clear that Tilmon is a player and could be one of the top 5 freshmen in the country.
And all of that just three days past his 15th birthday.
East St. Louis came away victorious over Decatur's MacArthur High School and Saint Louis University signee Marcus Bartley, who was impressive in his own right, but Tilmon was all smiles after the game.
"It was fun," Tilmon said of his first game. "I love playing harder. It went about how I expected. It helped me a lot playing against high school guys this summer."
One of the signature moments of the game for Tilmon was a monstrous put-back slam on a missed free throw. The whole gym erupted, and normally Tilmon would have, too, but he contained himself this time around.
"I love to yell after big moments," he said, "but I was kind of in the moment and just went back to the other end of the floor."
Tilmon got some early play over the summer at Riverside-Brookfield high school in a summer league. He was already one of the biggest there, but he learned what he would have to work on before the season got underway.
"I needed to get more aggressive in the paint," he said," but I feel like my skills help this year though."
A lot of times, it's tough, especially for a freshman, to jell with the team early on. With so much attention on Tilmon, he does what he can to deflect that to his teammates and help them get noticed, too.
"I'm very close with my teammates," he said. "We have a good bond together. It's very important, especially with the seniors. I have three more years, but I want to help them get where they want to be this year."
Over the summer, Tilmon also ran a lot with his younger teammates. That relationship is an important one to start now with those guys being his teammates for the next 3-4 years.
"I played with a lot of the sophomores this summer so that helped build a bond too," he said.
Despite the fact that up until Wednesday night Tilmon hadn't yet played a single high school game, he's already scored offers from some of the best programs in the midwest and could be in line for more before his season is even halfway done.
Proximity to home may play into this recruitment. It's still very early (emphasis on "very") but Tilmon does have a special place for the in-state program.
"I'd rather go to Illinois because it's where I'm from," he said. "I'd be close to home."
But his recruitment isn't a big deal to him right now. Actually, he's more concerned with the recruitment of his teammates, a very unselfish statement by such a young guy who is already receiving so much attention.
"I'm really just trying to get my seniors somewhere," Tilmon said. "Once I help them out, then I can focus on me."