Sparked by a record crowd, playing at home and with a formation switch, Atlanta United defeated D.C. United 3-1 on Sunday at Mercedes-Benz Stadium.

A league record 72,035 tickets were sold for the game, which saw goals from Josef Martinez, Miguel Almiron and Hector Villalba lift the Five Stripes to their first win this season and first at home in their past four (including last season).

It also helped the team erase the memories of the season-opening 4-0 loss at Houston.

“I think the team, after the game we had in Houston, the team picked itself up,” Martinez said. “Coming off a 4-0 loss and now playing at home we had to forget everything that happened. I think we had a very good first half. We started the second half a little asleep but the important thing is that we won and the three points stayed at home.”

Here are five observations about the game:

The formation change. After using the team's customary 4-3-3 or 4-2-3-1 formation in the loss at Houston, Martino switched to a 3-5-2 on Sunday.

It’s a formation that the team used some last season, worked on after the season and then continued to fine-tune during this preseason.

The team lined up with three centerbacks, two wingbacks on either side, one defensive midfielder, two attacking midfielders and two strikers.

Martino said he made the switch to get more players in the midfield to better aid the defense, and conceded that, even though it was used last year, the switch was made partly to help overcome the loss of defensive midfielder Carlos Carmona, who was sold before the season. The team is still trying to acquire another defensive midfielder before the transfer window closes on May 1.

Martino said don’t expect to see the formation for every game, but added that he’s glad that the team can play either.

The keys are how Darlington Nagbe and Jeff Larentowicz worked together in the middle of the pitch to disrupt counter-attacks on defense, and control the flow on offense.

Defensively, D.C. United had a difficult time creating numerical advantages in counter-attacks up the middle against Nagbe,  Larentowicz and the centerback trio of Franco Escobar, Michael Parkhurst and Leandro Gonzalez Pirez, or up the flanks where Julian Gressel and Greg Garza worked tirelessly to keep the team from getting too narrow.

“It’s something that we thought was opportune today to try it,” Martino said. “Because against Houston I thought we were lacking bodies in the midfield and the ability to recover the ball in the midfield. We thought it was a good chance to try it today and I think we did a good job for the first 75 minutes of the game and then we let off a little bit in the last 15.”

The big guns. Martinez, Almiron and Villalba looked like their old selves for must of the game.

The first goal, scored by Martinez in the 24th minute, came on a pinpoint pass from Villalba that split a defender’s legs behind a defender chasing Martinez and just in front of an onrushing David Ousted. It was a 1-in-10 pass-and-goal that the duo executed perfectly.

Villalba and Martinez said they work on those scenarios in training.

Martinez said he works on the run to the back post, and Villalba said they only need to make eye contact to know what the other is going to do.

Almiron’s goal in the 73rd minute was a left-footed shot into the upper left corner. He missed a similar shot in the first half.

“Almiron is one of the best I’ve ever seen in this league,” D.C. United coach Ben Olsen said. “They are a good team, don’t get me wrong, but he is special. He’s nasty and he makes them tick. Today he showed up and played very well.”

Villalba’s goal came on a header off a short corner. It’s a play he said the team works on. Running to the front post, Villalba was supposed to flick the ball to the back post for a teammate to run onto. He said he hit it a bit too hard, so it went into the goal’s opposite corner.

It was the first time that the three players have scored in the same game since doing so against Columbus on June 17 at Bobby Dodd Stadium.

Beating D.C. United. Lost within the excitement was that Atlanta United finally defeated D.C. United.

Despite being arguably the worst team in MLS last season, D.C. United beat the Five Stripes three times last season.

Those lost nine points cost Atlanta United the second seed in the Eastern Conference playoffs.

Sunday’s win was important for three reasons:

It earned the team three points.

It showed that the drab execution in the 4-0 loss at Houston the week before was an anomaly.

“I think it was the intensity that we brought,” midfielder Larentowicz said. “I think last week was like we were half asleep. One thing we wanted to focus on was just really getting that commitment. That was the word on the board, committing ourselves, playing with conviction, doing the things we do best. It seemed like last week we were second guessing ourselves so this week we wanted to put that away.”

Lastly, the win reaffirmed the team’s mental approach by knocking down the barrier that was D.C. United. The teams will play two more times this season: July 21 at Mercedes-Benz Stadium and Sept. 2 at D.C.’s Audi Field.

“That (commitment) was important, and it was important and interesting to see the response that we got from the team because we knew that was going to be important coming off the game against Houston where we made a lot of mistakes,” Martino said.

Attendance.  Atlanta United now has the three most-attended single games in MLS history, as well as the playoff mark. All were set in the first 10 games at Mercedes-Benz Stadium.

“It’s the stadium in general,” goalkeeper Brad Guzan said. “The atmosphere that our supporters create, whether it be the die-hard supporter or whether it be the casual fan, if you will. I don’t think we really have a casual fan here, I think that everyone kind of joins in the atmosphere in the singing and the chanting and that’s what makes it fun.”

Atlanta United set the previous league single-game record of 71,874 against Toronto on Oct. 22, 2017. That mark broke the record of 70,425 it set against Orlando City on Sept. 16.

Atlanta United’s reported attendance was more twice as large as the next best (26,221 at Yankee Stadium for NYCFC) in MLS last week.

“Next game we hope to see 73,000,” Martinez said. “We thank them because the support is always important, but we don’t want to stick with 72,000, we want 73,000.”

Atlanta United’s game on Sunday had the fourth-highest attendance among soccer games around the world last week.

Atlanta United also set a league record for average attendance (48,200) last season.

“I’ve been doing this for 20 years, starting back with Columbus,” Olsen was quoted as saying in the Washington Post. “I was in awe then. And now to see from there to this city [stadium] that they’ve built, the amount of people they packed in here, the noise, it’s exciting to be a part of.”

What's next. Atlanta United will host Vancouver at 7:30 p.m. Saturday. Mercedes-Benz Stadium will be at its normal capacity of 42,500, which means the upper deck will be closed and the curtains in place.

If the season-opening 4-0 loss at Houston was the worst performance in the team’s history, last year’s 3-1 loss at Vancouver has to be among the top five.

Using set pieces and a height advantage, the Whitecaps punished Atlanta United with two goals by centerback Kendall Waston. He scored four goals all season.

Giving up two goals on corner kicks at Houston probably doesn’t assuage the nerves of the supporters ahead of Saturday. But Martino said both of those goals at BBVA Compass Stadium were the result of individual errors and the Five Stripes didn’t give up a set-piece goal to D.C. United.

Vancouver is 2-0 this season with 2-1 wins against Montreal and at Houston. None of its four goals came from set pieces.