For the second straight year, the Union saw their run at the franchise's first trophy in its six-year existence end in frustrating fashion.
Jordi Quintilla connected on the winner Wednesday night as Sporting Kansas City captured the penalty kick segment, 7-6, after the teams played to a 1-1 draw through 120 minutes in the U.S Open Cup final before 14,463 at PPL Park.
Last year, the Union suffered a 3-1 loss in extra time to the visiting Seattle Sounders in the Open Cup final. In both games, the Union owned a 1-0 lead, only to see the visitors come back.
Before the Open Cup, Union coach Jim Curtin was quizzed on whether he would use Andre Blake or John McCarthy in goal.
It turns out he used both.
McCarthy had won the previous four U.S. Open Cup game, saving four penalty kicks in the process. He was inserted into the game in the 120th minute to handle the penalty kicks.
McCarthy stopped one shot and really had little chance at the others.
The Union's Sebastien Le Toux and Vincent Nogueira hit their first two penalty kicks, as did Sporting's Benny Feilhaber and Dom Dyer.
Union defender Maurice Edu and Sporting's Kriztian Nemeth each missed. Nemeth hesitated and McCarthy then blocked his low roller, diving to his right.
The Union's Tranquillo Barnetta, Conor Casey, Michael Lahoud and Ray Gaddis each scored, but KC kept matching.
Finally KC keeper Tim Melia blocked Andrew Wenger's shot, Quintilla then kicked the game winner and KC earned the automatic berth in the CONCACAF Champions League, the tournament that begins in August.
The Union took a 1-0 lead in the 23d minute when Le Toux tracked down the long pass from Nogueira and did what came naturally, especially in this stadium, in this setting and especially this tournament.
Already the all-time leading goal scorer in the modern era of the U.S. Open Cup, Le Toux increased his goal total to 16 in this event.
From just outside of midfield, Nogueira hit Le Toux in stride and he did the rest, one-timing a shot past a sliding Melia.
The Union survived Sporting's best first-half scoring chance when Paulo Nagamura rocked a shot off the right post in the 12th minute. The ball bounced right back to Blake.
In the 55th minute, a Kansas City goal was nullified when defender Chance Myers kicked Blake in the head while shooting. Blake, who set a team record with 10 saves in Saturday's 1-1 MLS draw at New England, lay on the ground momentarily but stayed in the game.
KC tied it on Nemeth's goal in the 65th minute. Shooting from just inside the box on the left side, his curling shot eluded a diving Blake.
Shortly after being inserted in the game, Union forward Conor Case took a feed from Tranquillo Barnetta and kicked a shot right at a sliding Melia from just outside the six-yard line on a right angle.
The Union's final good chance came when Edu headed a Le Toux corner in the 117th minute just wide.
Then came the penalty kick segment and more heartache for the Union.