PHILADELPHIA—It was not easy and it was not pretty, but for everything this game lacked, the U.S. men's national team made up for in grit, hard work, and sheer determination. The reward was a 1-0 win over Paraguay and a berth in the Copa America Centenario quarterfinals as the winner of Group A.

There is a lot to take away from the game. The U.S. rallied with its back against the wall and seemed to will itself to a win. Even before the red card, Paraguay had the better of play but the Americans made their possession count. As a result, it was almost the exact opposite of the game against Colombia.

Here are my thoughts on the game. 

1. Brooks' Immense Performance

Before the Paraguay match even began, John Brooks was the most valuable player for the U.S. at the Copa America and the two friendlies that led up to it. He had shown signs of impressive growth and improvement in each contest.

On Saturday, he was on another level, head and shoulders above everyone else—both literally and figuratively. He was challenged over and over and prevailed every time. In the 10th minute, Brooks made one of the most impressive plays you’ll ever see from a central defender when he tracked back quickly and broke up a three-on-one counter for Paraguay.

Jurgen Klinsmann seemed to grasp the enormity of how well Brooks played but also calmly urged the media to not overhype him, as he is still young.

“John Brooks, with a performance like this, I guess all of Europe is watching that,” Klinsmann said. “This is a big statement, what he did tonight.”

“I am just impressed by the learning curve that a younger player has to go through,” the coach continued.  “You're just happy for that process. A year ago a lot of people were very critical of him. I said that he just has to have those experiences. He needs to make mistakes in order to grow. There is no growth without failure for anybody. He grew.

"That performance from John was really something special. But we've got to keep him grounded, please.”

2. Klinsmann answers critics again

This win was also a personal reward for Klinsmann who was embattled heading into the game with speculation over his job security. Now he has the team heading into the quarterfinals of the biggest men’s tournament played on American soil since 1994.

Klinsmann’s tenure as head coach of the United States national team began at Lincoln Financial Field in 2011 with a game against Mexico—and the German's debut was met with optimism from the fan base. Over the course of the next five years there have been many peaks and valleys but on Saturday night Lincoln Financial Field was the site of Klinsmann’s biggest win on American soil.

It was a pivotal game in which the U.S. needed a result, and unlike World Cup qualifiers or the Gold Cup, the opposition was a quality South American team that finished fourth and second in the two most recent Copa Americas.

But the ongoing theme is that whenever Klinsmanns becomes embattled, the U.S. national team responds. In 2013, the Yanks began a long winning streak that started ahead of the famous Snow Clasico, when doubts about Klinsmann surfaced at the start of the Hexagonal.

Then, after the loss to Mexico in the 2015 CONCACAF Cup, the U.S. started World Cup qualifying strong. Now in 2016, the team rallied again in Copa America Centenario.

Klinsmann finds a way to win when the chips are down. At this point, even critics should be impressed.

3. An Old-School American performance

In the end it was a distinctly American performance. This is how the U.S. used to secure wins over quality opposition.

The Americans did not dominate in the first half but found a bit of magic when they capitalized on a stellar individual effort from an unlikely contributor, Gyasi Zardes, who assisted on Clint Dempsey’s winner. Then, after a red card to DeAndre Yedlin, it was a collective defensive showing and some outstanding goalkeeping that finished the game out.

“You’ve got to give amazing credit to our veteran players,” Klinsmann said. “Clint finishing it off—being clinical, being Clint. Jermaine being a warrior all over the field. Michael running—I don't know how many [miles]. It's a team that is really having a good time and is there for each other. The whole bench is right there. No matter who you bring in, they will give it their all. It's fun to watch.”

Klinsmann later added: "They grinded it out."

4. Guzan Is the No. 1 Goalkeeper

Brad Guzan has been the starter for the U.S. in the past but always with an asterisk, always with the specter of Tim Howard coming back to the fold and reclaiming the spot. Guzan was shaky in last summer's Gold Cup. Then, at the start of World Cup qualifying, Howard would still occasionally start. When Klinsmann named Guzan the U.S. starter despite a rough year at Aston Villa, Howard’s presence still loomed large.

Against Paraguay, Guzan made his strongest statement to date that he is the No. 1. keeper and he will be the top choice for the foreseeable future. He impressively denied Dario Lezcano twice in the opening half, including a difficult stop in the 45th minute after Lezcano slipped behind the backline.

In the 82nd minute, Guzan made two stops in quick succession on Jorge Benitez and Miguel Almiron.

Guzan is the first-choice goalkeeper and now he’s stepping firmly into the spotlight in a long line that includes Tony Meola, Kasey Keller, Brad Friedel, and Tim Howard.

5. How will Yedlin respond?

In Saturday's post-game press conference, Klinsmann acknowledged that he had no disagreement with either of the yellow cards that Yedlin picked up in the opening minutes of the second half.

The Seattle native had recently won the starting right back job but he clearly lost his composure and put his team in a very bad position. Fortunately for Yedlin, his teammates bailed him out. But his mistakes will loom large as Yedlin is now suspended for the quarterfinal.

Young players frequently face obstacles and challenges. The question is, how do they respond? Has Yedlin’s confidence taken a hit or will he rebound and put this in the rearview mirror?

“The first reaction is: inexperience,” Klinsmann said of watching Yedlin’s second yellow card. “He got emotional. He got caught emotionally. He made the first tackle because he has to make that recovery run... then he just lost his head for a second. This is why you are young.

"You've got to give him the benefit of the doubt. You've got to give him that credit. He will learn out of that mistake and just cool down for a couple of minutes and find your path in the game again.”

Brian Sciaretta is an ASN 100 panelist and a contributing editor. Follow him on Twitter.