The team's previous goal scored was from midfielder Luke Mulholland more than a month ago, a 3-1 loss to the Portland Timbers on June 7. RSL was also in the midst of a string of shutouts, failing to score at all in four of its last seven matches.
Production from the forward spot has been even worse in this stretch, the last run of play goal coming from Plata in a 2-1 win over Colorado on May 17.
Cassar downplayed the effect of the open-play goal after a couple of penalties in the last few matches, but he praised the build-up and team play that led to the goal.
"It was great. It was a nice build-up, it was excellent," Cassar said. "There's a lot of talk of not scoring through the run of play, but we got two PKs, that's through the run of play, so we've earned those. We've just got to continue pushing forward."
Forward Devon Sandoval and his sub on the night, Robbie Findley, have both yet to score this season, while Plata leads the team with eight goals in Alvaro Saborio's absence.
Kyle Beckerman, who played the final ball to Plata for the goal, said the forward called for the ball.
"I heard Plata screaming for it and I knew he was wide open," Beckerman said. "I played it and he just did the rest."
However, the midfielder said there's still work to be done after a few missed chances following the goal.
"It felt good, but it felt like we were going to get another one," Beckerman said. "I really felt that it brought some life to the crowd and I figured we'd get another chance, which we did. We've just got to keep working and keep trying to get better."