COLUMBUS, Ohio — Already missing nine regulars for an array of reasons, D.C. United on Wednesday watched goalkeeper Bill Hamid limp off the field not long after the Columbus Crew’s black-and-gold clad supporters filed into its new downtown stadium.

But as Coach Hernán Losada noted after the surprising 4-2 victory, “This team has had so many obstacles and difficulties, that makes us stronger.”

Losada filled the voids with players who understood and embraced their roles, and in a stirring first half, United scored three goals against the reigning MLS Cup champions. D.C. conceded two midway through the second half before securing just its second away victory of the season and improving to 7-7-3 at the midway point of the league schedule.

“No matter who is starting, no matter who is playing, they are just giving their life for each other,” said Losada, whose team is unbeaten in four matches (2-0-2) and 3-1-2 over its past six.

Ola Kamara continued his scoring tear with two goals and Yordy Reyna posted his first two of the year as United handed Columbus (6-5-6) its first defeat in four home appearances since Lower.com Field opened last month and first home setback since last October.

Kamara scored in his fourth consecutive appearance and increased his season total to nine, joining the other league leaders. Seattle’s Raúl Ruidíaz began the day atop the list with 11.

Before the match, Losada tried motivating his team by pointing to the Crew’s home streak. He also brought up the MLS All-Star Game roster: no United players among the 28 selections that will face the Mexican league stars later this month in Los Angeles.

Losada called it “painful because I believe there are many on our team who deserve to be there. Maybe it’s due to the fact D.C. wasn’t good enough the last couple years and lost a little bit of respect. Little by little, with this big heart and fighting spirit, we are coming back.”

United on Wednesday was without five injured regulars, two U.S. national team players recovering from Gold Cup duty and two players serving red-card suspensions.

The personnel issues deepened when Hamid rushed out of the box to break up a threat. He appeared to injure his right hamstring and needed assistance leaving the field, prompting former Crew keeper Jon Kempin to enter in the 17th minute.

Two minutes later, however, United went ahead. Reyna pressured Aboubacar Keita into a giveaway a few strides outside the penalty area. Kamara collected the stray ball and cruised in alone before beating Eloy Room. Out of respect for his former club, Kamara did not celebrate.

The lead grew in the 40th minute on an outstanding delivery and finish. Andy Najar provided the cross from left corner to the heart of the box. Reyna ran toward the ball and used terrific technique to twist his body and angle a downward, 11-yard header into the back corner.

As seven minutes of stoppage time commenced, the Crew’s star defender, Jonathan Mensah, lost the ball at the edge of the penalty area. Kevin Paredes took possession and, as he raced into the box, was upended.

Kamara converted the penalty kick, again keeping the excitement to himself as his players embraced him.

“They’re down 3-0, and the fans are booing them,” Kamara said. “That was a great feeling.”

Returning from a one-game absence for concussion protocol and needing to be ready for a weekend match, Kamara was rested in the second half as Losada added defensive reinforcements.

D.C.'s miscues in the 65th minute resulted in a goal and re-energized both the Crew and the 18,398 supporters. Kempin came off his line to break up a pass. Gyasi Zardes tracked the ball and crossed. Frédéric Brillant spilled it to Kevin Molino for a blast into the top of the net.

The Crew struck again in the 71st. Molino hit the crossbar form distance, with the rebound falling to Lucas Zelarayán for a close-range volley.

Everything seemed to be flowing Columbus’s way, but on a counterattack, Reyna took on Keita, cut inside and whistled an 18-yarder into the far corner. The Crew was all but done.

“Today was about efficiency,” Losada said, “but also how we scored the goals.” Two came via high pressure on defenders, one through the Najar cross and another on the counterattack.

“This is huge,” Kamara said of the rare victory by United in central Ohio. “If we can keep working hard and be humble, this [could be] a really good moment for the team.”

Notes: Because of the personnel shortage, rookie defender Jacob Greene, 18, was recalled from second-division Loudoun United. D.C. still had only seven available subs, two fewer than is allowed. … D.C. will host CF Montreal (6-6-5) on Sunday night.

Read more on soccer: