In a match light on clear cut chances, Palace controlled the majority of proceedings, with Jean-Philippe Mateta's header in the 30th minute opening the scoring.
Jefferson Lerma, who assisted the first, created the second when his long throw-in was diverted into the Brentford net by Bees defender Nathan Collins not long after half-time.
Both goals came directly from a set-piece situation and Glasner said that a lot of Palace's limited time on the training pitch ahead of the Brentford match, following the midweek win against Liverpool, was spent on this aspect of the game.
"I told everyone in the pre-match press conference that they scored two and we scored two from long throw-ins," he said. "To be honest we didn't have too much time to work on the the training pitch.
"Thursday was recovery and then yesterday we trained 25 minutes on the pitch, then 15 minutes on throw-ins, both defending and attacking.
"We knew this would be a topic today. So credit to my assistants who prepared all the clips and the set-up.
"We spoke about it and said it could be a ‘set-play battle.’ And I think in the end we won the set-play battle. We scored two goals [from set-plays] and that's why we could win the game.
"It's a very, very important and good win today."