TIJUANA, Mexico—This weekend’s MLS Cup final may be front of mind for most American soccer fans, but on Thursday and Sunday, several of the United States’ young stars will be playing for a championship of their own—in Mexico’s Liga MX Apertura final.

In just its fifth year in existence and second year in the top flight, Xolos of Tijuana, featuring U.S. Men’s national team regulars Edgar Castillo of New Mexico and local talent Joe Corona, as well as U-23 member Greg Garza of Texas, take on 10-time champion Toluca.

These two teams finished first and second, level on points in the regular season, but traveled different routes through the playoffs to the final. Toluca, which took the No. 1 seed due to goal differential, beat Chivas 5-2 on aggregate, then got past America despite narrowly losing the second-leg match. Xolos, meanwhile, overcame a favored Monterrey side with years of tournament and postseason success, then overturned a 2-0 first-leg semifinal defeat in a hostile atmosphere in Leon with a sensational, last-minute 3-0 win in Tijuana on Sunday after they’d been largely written off.

“The whole team knew it wasn’t over [after the first leg], and that we still had a lot of chances of passing to the final,” Corona told ASN this week. “Coach [Antonio Mohamed] made us believe that we were still alive, and he set up a very offensive squad because we needed two goals. Our strategy was to come out offensive, but we knew we had to be patient.”

Garza agreed with his teammate. “Turco (Mohamed’s nickname) told us to go out there and do what we had done the entire tournament. The day after we had lost the first leg in Leon, we were not worried at all, and kept our confidence and heads high knowing that we could pull off a win at home,” he said.

True to the game plan, Xolos opened the scoring right before halftime, then Colombian forward Duvier Riascos made it 2-0 in the 68th minute. But when Richard Ruiz scored the tie-breaker in the 90th minute to send Tijuana to the final, the Estadio Caliente went bonkers.

Garza said the atmosphere in the locker room after the game was “crazy, but at the same time knowing that it is not over. We had definitely climbed a huge wall and achieved what was wanted to be achieved, but we are still missing a small piece of the whole entire cake. It is a dream come true so far, but we all know that we can give a little more to make it even better.”

“The locker room was full of happiness, for me one of the best games I've experienced in my life,” Corona said. “We knew we had done what people thought was almost impossible. Everybody is very motivated for the first game on Thursday and on the same page. We have to now focus on getting the win.”

In their meeting in the regular season, Tijuana beat Toluca 1-0 at home, thanks to a goal by Riascos. For the second season running, Tijuana has one of the stingiest defenses in the league. But in this Apertura season, Toluca scored the most goals away from home of any team in Liga MX. And while Tijuana is playing for a first-ever league title, Toluca is going for their 11th, which would tie them with Chivas for the most all-time Mexican championships.

With those kinds of stakes, Corona knows what Tijuana have to do.

“We have to want it more than Toluca—I believe that we have to come out with the same mentality we did against Leon.”

“Toluca is a team that has a lot more experience than us in playing in finals, but we know that we have the talent and a good enough team to make history within the Mexican league—and from the very first minute we will be looking and searching for the win here at home and in their stadium,” Garza added.

While a championship would be a storybook ending for this upstart, unheralded side and its American internationals, by reaching the Apertura semifinals, Xolos have already booked their place in South America’s Copa Libertadores, as well as the CONCACAF Champions League—invaluable experience for these young national team members.

The first leg in Tijuana is Thursday at 10 p.m. ET on Univision Deportes. The second game in Toluca is Sunday at 7 p.m. ET on Univision.

Adam Elder is a journalist who writes for The New York Times Goal blog, Wired.com, and other publications. Follow him on Twitter at @adam_elder