United forward Conor Doyle, right, and Chicago’s Gonzalo Segares battle for the ball. United needs to win two of its final three matches to avoid equalling or setting an MLS record for fewest wins. (Toni L. Sandys/The Washington Post)

A peculiar scene unfolded late Friday night at RFK Stadium: D.C. United players lifted a trophy at the conclusion of a 3-0 defeat to the Chicago Fire, a setback that pushed the club closer to MLS futility.

It was, for sure, a contradictory moment. Given how the season has unfolded, it seemed fitting.

United won the U.S. Open Cup on Tuesday in Salt Lake City, then resumed its miserable regular season with another defeat.

“It would have been nice to get a win and celebrate the right way toward the end by lifting up the cup,” captain Dwayne De Rosario said after the players showed off the organization’s 13th major honor to those in the crowd of 13,949 that stuck around.

Instead, United reverted to bad habits and a record-threatening trajectory. Regular season results have not meant much to United (3-22-6) for months, but in the aftermath of the upset against Real Salt Lake, Ben Olsen sought a strong finish to the bumbling MLS campaign.

The good vibes carried into the early stages, but after a series of classy saves by Fire goalkeeper Sean Johnson, D.C. conceded goals two minutes apart midway through the first half and never regained its gusto.

Winless in nine straight league matches, United will need to win two of the final three to avoid equaling or setting the league record for fewest victories (four).

Jeff Larentowicz scored in the 24th minute and Bakary Soumare struck in the 26th, increasing the number of goals conceded by United in the first 30 minutes of matches to 21 (out of 54 overall). Substitute Quincy Amarikwa added an 89th-minute goal.

Due to the quick turnaround from the Open Cup, Olsen retained just four starters: Perry Kitchen, James Riley, John Thorrington and Nick DeLeon. Kitchen, a defensive midfielder, started at center back.

While United is closing the season, Chicago (12-12-7) is in a congested playoff race in the Eastern Conference and could ill-afford to drop points against a last-place opponent.

Despite the personnel gulf, United rode the momentum of the Open Cup outcome and caused trouble. In the first 14 minutes, Johnson made expert saves on Conor Doyle and Luis Silva, and Jared Jeffrey smacked the left post from 25 yards.

United’s Joe Willis was tested as well, stuffing Mike Magee from short range.

“We wanted to come in here and not have a hangover from the Open Cup, to end the season with momentum,” Riley said. “The first 20 minutes were very bright.”

But then the match turned. With bullish power and ingenious footwork, Juan Luis Anangono beat Daniel Woolard and Riley before slipping the ball to Larentowicz inside the six-yard box for a quick and angled finish.

Two minutes later, United failed to clear Mike Magee’s free kick into the box, allowing Soumare (University of Virginia) to smash an eight-yard one-timer for his first regular season goal in 86 appearances.

Johnson’s mastery continued with a splendid reaction stop on DeLeon. In the second half, he thwarted DeLeon twice with outstanding saves.

Amarikwa sealed the outcome by redirecting Dilly Duka’s cross.

United notes: De Rosario and Dejan Jakovic will depart Monday for London, where the Canadian national team will gather ahead of an Oct. 15 friendly against Australia at Fulham’s Craven Cottage. While away, the pair will miss next Saturday’s home match against the Philadelphia Union. . . . Thorrington departed late in the first half with a calf injury. . . . United was shut out for the 15th time.