IT WASN'T PRETTY, but the team got what it came for.

A first-half stoppage-time goal from Rubio Rubin was all the U.S under-20’s men’s national team needed to emerge undefeated from group play at the 35th annual Dallas Cup youth tournament. Needing only a tie to advance, the Americans walked out of the Cotton Bowl on Wednesday night with a 1-0 win over UANL Tigres and a ticket to the U19 Super Group semifinals, where it will face Brazilian side Fluminense on Friday night.

Head coach Tab Ramos trotted out a strong, attack-minded lineup that featured his top performers from the tournament’s opening two days: Rubin, Paul Arriola, Jordan Allen, Benji Lopez, and Ben Spencer all buzzed around the Tigres penalty box for the U.S.

The powerful lineup also saw the inclusion of returning New York Red Bulls defender Matt Miazga—who impressed on Wednesday—getting the nod alongside Michael Amick in the center of defense. Shaq Moore and Lynden Gooch both made their third consecutive starts of the tournament.

It was a physical, back-and-forth match from the opening whistle. The Americans set the tone early by probing the Tigres backline, but were unable to find many real opportunities. The best chance of the opening half hour came when a corner kick from Arriola found the head of Ben Spencer, who grazed his effort off the top side of the crossbar in the 25th minute.

Tigres had to rely on an indirect free kick for its best opportunity of the first half, when goal keeper Zack Steffen was whistled for the little-seen delay of game penalty. Fortunately for the young keeper the ensuing try from 15 yards was easily snuffed out by the U.S. wall.

The breakthrough for the Americans came seconds into first-half stoppage time when Rubin received a sharp pass from Moore on the outside of the box, dribbled past three Tigres defenders, and slotted a low-driving, left-footed effort in the bottom corner for his second goal of the tournament. It was a gut punch for the Mexican side who had limited the Americans to only four shots in the first half.

Without much to play for, Tigres tried to play spoiler. It was a questionable strategy, as its continual time-wasting and over-the-top physical play disrupted the game but not the U.S. resolve. In a humorous moment, a Tigres player attempted to draw a foul with a shameless dive, only to receive a yellow card for his troubles after stalling and asking to be carried off the field.

Playing a man advantage, Arriola nearly scored what likely would have been the goal of the tournament. Off a deflection in midfield, Miazga gracefully popped up the ball into the path of the American captain who hit a sizzling volley that kissed the top of the post from 30 yards out—a strike prompting flashbacks of Michael Bradley’s 2012 stunner against Scotland.

Emboldened by Tigres’ outward capitulation, the talent of the current U-20 pool was highlighted during several bright sequences, including one eight-pass movement that saw Pfeffer, Arriola, and Rubin combine beautifully, only for substitute Romain Gall to put his effort excruciatingly over the crossbar.

Although the Americans sought an insurance goal, the remaining quarter hour played itself out with little excitement, with the Americans throwing out five defenders in the final 10 minutes to secure the victory and finish atop its group with three consecutive wins and a +5 goal differential.

After a day-off tomorrow the squad will face Fluminense on Friday, a team that defeated RSC Anderlecht 3-1 on Wednesday afternoon to top Group B. The winner of that contest will face either Cortiba—which knocked off defending champion Fulham earlier in the day—or River Plate, which put up seven goals in a demoralizing beatdown of Eintracht Frankfurt to earn a semifinal wild card spot.

Friday’s match will kick off at 8:30 pm ET and will be streamed online at TWCSportsChannel.com.

ASN Contributing Editor Josh Deaver is a former academic turned soccer obsessive. Follow him on Twitter already.