Jocelyn Vasquez earned the win for the Maroon and Gold, striking out 11 Tigers from the circle while walking just two. Sparks committed two errors in the field.
At the plate, the Railroaders rapped out 10 hits. Marissa Cossio led the way as she went 2-for-3, including a double and three RBI. Madison Franco was 2-for-2 with one batted in.
"Portola is a good team but our kids played disciplined," Sparks coach Frank Avilla said. "They did real, real well today."
Sparks (5-7) will now host Elko on Friday at 4 p.m. as it kicks off a trio of games against Ruby Mountain League foes.
"We just have to continue to stay disciplined," Avilla said. "They're starting to just play catch out there so if they continue to do that and we continue to keep shoring up our errors, than we'll continue to improve. They believe in each other. I think we're making a run. I think we're going to be OK.