Burroughs knotted the match at 3 on a goal by Danny Maireno with about two minutes to go in the first half before Riverside Poly took a 4-3 halftime lead with a goal in the closing seconds.
Burroughs Coach Danny Garcia said the Indians were confident they could mount another second-half surge and extend their season.
“We are a team that usually struggles in the first half and then plays very well in the second half,” said Garcia, whose team recorded an 8-6 wild-card win against Bonita on Tuesday. “Things just broke apart in the third quarter and we fell behind, 9-5.
“We ran into some foul trouble throughout the game. We had 10 ejections and they scored on seven man-advantage chances. A few times, we had bad positioning and they were able to get the ball into the hole/set and score. We hung in there. It’s the first time where things didn’t really pan out for us in the second half.”
Maireno finished with a pair of goals for the Indians, who received one apiece from Kevin Ueno, Joe Jacobson and Oscar Hernandez. Burroughs goalkeeper Dillon Weigand finished with five saves.
Garcia said the Indians met their preseason goals.
“We wanted to finish in the top four in league after taking sixth the last couple of years and make it to CIF,” Garcia said. “We did both of those things, plus we won a playoff game.
“We have most of our guys coming back next year. They got a taste of the playoffs and know what it will take to get back there again.”