When Jack McInerney streaked in and scored an 88th-minute equalizer, Sporting KC looked destined to settle for a draw, but Peter Vermes' squad never stopped playing and showed the resliency of a team capable of a championship run.
Lawrence Olum finished off a pass from Teal Bunbury in the second minute of second-half stoppage time for the winning goal in a 2-1 victory at PPL Park on Saturday.
The Union equalized late when McInerney raced onto a long headed pass to tie the match, but as Philadelphia pressed for a winning goal, it was Sporting KC that looked more dangerous in the closing minutes. Bunbury came on late and provided a real dangerous threat, forcing a big save from Zac MacMath a minute before setting up Olum's winning goal.
The victory pushes Sporting KC into first place in the Eastern Conference, and now KC must await the result of Sunday's match between the New York Red Bulls and Chicago Fire. A Red Bulls win would give them the Supporters' Shield and first place in the East, but a New York loss or draw would give Sporting KC the Shield and the top spot in the East heading into the playoffs.
"What I'm really happy with is how we responded after their goal, and how much we still had left in the tank," Sporting KC head coach Peter Vermes said. "The determination to finish that game off impressed me, and they were spent. It wasn't an easy second half, with them throwing everything at us. We overcame that and still found a way to win that game."
In a match with so many recognizable attacking players, it was Olum who stepped up to deliver for Sporting KC, scoring his first goal since 2011, when he tallied a goal in the USL Pro final for Orlando City.
"We're a tough team and we've had good continuity through the years with this group, so you can see that experience in how we finished that game," Olum said.
After a scoreless first half, Graham Zusi opened the scoring just two minutes into the second when he headed home a Matt Besler throw-in deflected toward him by an Olum header. It was Zusi's career-high sixth goal of the season.
The Union trotted out an unconventional lineup, with Sebastien Le Toux and Jack McInerney on the bench to start the match, and with Amobi Okugo playing in central midfield rather than his usual center back role. The squad struggled to generate chances against Sporting KC's league-best defense, but Philly's attack showed more promise after going down a goal.
Union coach John Hackworth inserted McInerney and Roger Torres in the second half, as well as LeToux, and the inclusions did provide a spark, but Sporting KC's defense once again proved too tough to break through until McInerney found his opening late in the match.
The late goal wasn't enough to keep the Union from being eliminated from playoff contention for a second straight season. The young squad showed signs of improvement in 2013, but will head into next season with more question marks about what sort of roster upgrades the team can pull off to complement a talented young nucleus that includes McInerney, Okugo and goalkeeper Zac MacMath.
As for Sporting KC, the current East leaders can do no worse than second place in the Eastern Conference, meaning a guaranteed place in the East semifinals. By Sunday, if the Red Bulls lose or tie, Sporting KC could be lifting a Supporters' Shield and playing for the chance to host the 2013 MLS Cup final.