Colorado's goal came via a controversial penalty kick goal that was converted by Conor Casey. Union defender Danny Califf was whistled for a foul in the area for pulling on the shoulder of Rapids midfielder Pablo Mastroeni. Casey then cheekily lofted the ball right down the middle into the net on the penalty kick.
The Union were not going to give up, however. Four minutes later, in the 66th minute, the Rapids gave Mwanga far too much space near the penalty area and the young Congolese striker turned and fired the ball past Matt Pickens for the equalizer.
The draw was Colorado's sixth in a row, which sets a new record in Major League Soccer. More on this game after the break, including the full match highlights.
With Carlos Ruiz now officially away with the Guatemalan national team, coach Peter Nowak shook up the starting eleven for the Union. Jack McInerney was handed a rare start at striker alongside Sebastien Le Toux, while Brian Carroll started as a lone defensive midfielder behind Justin Mapp, Kyle Nakazawa, and Gabriel Farfan.
Early on, the lineup seemed to be working as the Union controlled possession in the opening portion of the game. Kyle Nakazawa's effort off a free kick was saved in impressive fashion by Pickens in the 11th minute.
Unfortunately, that early momentum seemed to disappear when Justin Mapp had to leave the match with a hamstring problem in the 25th minute. For the rest of the first half, Colorado were able to dictate much of the play, just like the Union had done before Mapp's departure.
In the second half, the Union were presented with what was arguably the best chance of the game. Gabriel Farfan played a beautiful low ball across the penalty area in the 53rd minute that made its way to the feet of Keon Daniel. The Trinidad & Tobago international had a fairly open net to aim at, but he sent it sailing over the bar.
The penalty drama occurred in the 62nd minute. While many Union fans will be disappointed with the referee's decision, Mwanga was able to save the team once again, just as he did in the home game against Los Angeles. His goal gave the Union a valuable road point against the defending champions.
It comes as an even better result given the home draw that the New York Red Bulls earned against Columbus earlier in the day. The Union remain in first place with 21 points to New York's 19, and the Union have only played 12 game to New York's 13.
The Union return to PPL Park next Saturday to face Real Salt Lake, whose starting lineup has been depleted recently by Gold Cup call-ups.
Here are the full match highlights: