The hosts launched wave after wave at the Guatemalan side, but could only muster a two-goal win on a night when much more offence was required.
Daniele Paponi and Andrew Wenger tallied for the Impact on a night where the home side needed to win by five goals in order to stay alive in the continental competition. It very well could have been five or more for Montreal given the run of play, but some unlucky finishing and a standout performance by Heredia goalkeeper Jose Calderon conspired to limit the hosts to just the pair.
Paponi opened the scoring in just the fifth minute of play, and the sheer number of chances by the Italian and strike partner Wenger in the early going made it look like the Impact were set to rout their Guatemalan visitors.
However, Montreal couldn't capitalize on a dominant first half and had to settle for a 1-0 lead after 45 minutes. The scoring woes would extend into the second half, as the hosts poured on the pressure but simply couldn't convert.
Wenger finally made up for his missed opportunities early after the restart, latching onto a through ball in the 54th minute and slotting past the onrushing Heredia goalkeeper to double the home side's lead. From then on out, it was nearly total one-way traffic as Marco Schallibaum urged his players to push for the required scoreline.
To that end, MLS-leading scorer Marco Di Vaio was brought on for the final half hour. In addition, Justin Mapp and Blake Smith entered the contest in the second half, and the Impact predictably controlled proceedings for the closing portion of the match.
Despite the offensive thrust, the Impact could do little to improve their goal tally and stay alive in the tournament. The woodwork was struck a couple of times, and a bevvy of wayward shots were launched at the Heredia net, but in the end the 2-0 score would hold up.