POMONA - Five months ago, the entrants in a regionwide competition Thursday were just bags full of legos.

By Thursday's competition, the bags had been transformed into wheeled mechanical figures with minds of their own and, for some, the strength to crush and destroy their robotic competition.

The transformation came at the hands of teams of sixth- through eighth-grade students from across the region, participating in the STEM Through Guided Discovery fifth annual Robot Rally at Cal Poly Pomona.

From outside of the school's College of Engineering building, the nearly 300 students could be heard whooping and hollering in hopes that their robots would secure victory.

The "sumo" competition featured two robots going head to head, each trying to knock the other off a platform.

"We were going to try to win first place for our school since it's our last year," said 11-year-old Marco Polo, who along with his teammates from Shelyn Elementary School in Rowland Heights, designed, built and programmed the robot "Bruiser."

"Bruiser" went eight rounds before reaching the finals, but the bot lost after being knocked off the platform twice.

"We were so close, man. So close," said fifth-grader Edison Chow, 10.

"We're still happy we got second place," added teammate Christopher Garcia, 12.

One round away from the semifinals, another group of Shelyn students suffered a loss when their creation, "Angry Robot,"

Still, despite the disappointing losses, Rowland Unified came out on top - the winner of the sumo competition came from one of its middle schools, Rincon Intermediate in West Covina.

Bethany Hernandez, 13, and Racel Suyat, 14, won with their creation, "Boo."

"It was unexpected," Bethany said of coming in first place, adding that their robot initially did not function very well. "There were other people with better robots that we thought would win."

Although they procrastinated in building the bot and programmed it at the last minute, the pair was motivated.

"It was fun and cool to be part of the engineering class," Polo said.