That was a 1-1 draw against Real Salt Lake, another game the Union dominated, especially in the first half. Unlike Kansas City, Real Salt Lake is among the better teams in MLS, albeit one without many key components against the Union because of injury and national-team duty.
Still, Real had just one scoring chance, and converted it.
So the word has gotten out around the league that PPL Park is a difficult place to earn points. No doubt the fans, led by the Sons of Ben, give the Union a major home-field advantage.
In this case, the record doesn't lie. The Union are 4-0-4 at home.
Only Los Angeles (4-0-4) and Kansas City (1-0-1) are also unbeaten at home this season.
Union goalkeeper Faryd Mondragon, who has recorded four of his five shutouts at home, where the Union have outscored teams by 8-4, had an interesting take on Kansas City's approach.
"It's a tactic and the way they chose to play, and you have to respect that," Mondragon said. "Our job is to try to get the solution and find a way to break all these defensive tactics."
Of course, while it might be frustrating to play a team that is clearly back on its heels, the easiest way to solve this puzzle is to put the ball in the back of the net.
On one hand, the Union have to be encouraged that they created so many opportunities against Real and Sporting. On the other, they can't be happy at the inability to finish the deal.
Against Real, the Union could have easily led by 3-0 at halftime, but instead held just a 1-0 lead.
The difference in the Kansas City game was that the Union were aggressively on the attack the entire contest. Salt Lake at least made adjustments and took the play more to the Union in the second half, when it scored the equalizer.
The Union were without Danny Mwanga on Wednesday, after he hurt his knee in Saturday's 1-0 loss at Vancouver. Of course, Mwanga was inserted in the second half of the loss to the Whitecaps, and the offense still sputtered.
The Union did everything they could to spice up the attack against Sporting, including moving the defenders up even further than usual during the second part of the second half.
Maybe it has surprised the Union that teams are affording them this type of respect, yet it's up to them to not only keep attacking, but also to show they can take advantage of the many scoring chances they've been creating, especially at PPL Park.
"It's not going to get any easier," Union team manager Peter Nowak said. "I think that the teams are recognizing that they can come here and just play defensive and look for the goal, look for the counter."
Now it's the Union's turn to counter and to show opponents that playing not to lose at PPL Park will turn into a losing proposition.
Contact staff writer Marc Narducci at 856-779-3225, firstname.lastname@example.org, or @sjnard on Twitter.