With the game scoreless, Olmes Garcia drew a foul on Houston's Adam Moffat in the box and Saborio converted the ensuing penalty kick for his fifth goal in three games.
RSL (12-7-5) regained the lead for the Supporters Shield -- indicative of the best record in the league -- with the victory.
The Dynamo (9-7-6) fell for the first time in five contests.
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