A few days after stealing their most surprising win of the year, the Union delivered what might be their most impressive.

With nine starters rested ahead of Wednesday's U.S. Open Cup final, a squad of backups took down Western Conference-leading Sporting Kansas City, 2-0, on Sunday at Talen Energy Stadium. Jay Simpson scored both goals in his first start of the season, and just his fourth appearance.

"Before the game, we talked about what it means to be a true team," Union manager Jim Curtin said. "Any 11 guys that are together fighting for each other with belief, attacking and defending as one, can beat any group of talented players. … The players deserve all the credit in the world for the result today."

The only regulars on the field for the Union (14-12-4, 46 points) at the kickoff were Auston Trusty and Borek Dockal. Fabinho, Fabian Herbers, Derrick Jones and John McCarthy got rare opportunities to start, and 21-year-old Cameroonian right back Olivier Mbaizo made his Union debut.

There was clearly a lack of shine from the understudies, but there was no lack of effort. An example came in the 35th minute, when Herbers hit a 20-yard rip that was deflected up off the crossbar. On the rebound, Simpson was denied by a reflex save from Kansas City (15-8-6, 51 points) goalkeeper Tim Melia and a goal line clearance by Seth Sinovic.

McCarthy was asked to start just an hour before kickoff because Andre Blake was sick. He was more than serviceable, making two saves in the first half and four in the second.

Simpson's first goal came in the 71st minute off a well-worked free kick. Auston Trusty took it from midfield, launching a service into the 18-yard box. Alejandro Bedoya, who replaced Dockal early in the second half, beat Sinovic to head the ball toward Simpson, and he struck a fine volley from 16 yards.

The second came in the 90th, again with Bedoya's help. Fafa Picault whipped in a left-footed cross from the left wing after a nifty cutback, and an unmarked Bedoya charitably headed the ball down for Simpson to finish.

"I'm sure a lot of people didn't really fancy us, even today, to get a result with a lot of our starters missing out," Simpson said. "Everyone's confident going into the Open Cup [final]. The team that usually starts are confident, and the boys who played today, I'm sure that gave us a lot of confidence going forward, as well."

Simpson could speak to that better than anyone.