San Marcos softball erupted for eight runs in the fifth inning to earn a 10-0 mercy-rule win over Leuzinger in the CIF-SS D5 opener on Friday in Santa Barbara. The Royals will have a quick turnaround for round two, as they are set to take on University High on Saturday in Irvine at 12 p.m. “We really won that game in our warm-ups. We think we started with great energy, and we started really focused,” San Marcos head coach Emily Dietz said of Fri…