Laguna finished 17th at last year's tournament.
Laguna and host Mater Dei played to a 9-9 tie Tuesday at Los Caballeros Racquet Club and after 18 tie-breakers, the Monarchs emerged with a 10-8 victory.
The match, which began at 3 p.m., ended at 7 p.m., Laguna interim coach Jonee Earl said.
Laguna's No. 1 singles player, Lyndsay Kinstler, and its No. 1 doubles team of Lauren Thigpen and Heather Tran, earned sweeps. No. 2 singles Madeline Jaeger won two of three matches, and No. 3 singles McKenna Nokes picked up another point.
Kinstler is now 10-0 on the season.
"It just couldn't have been a tighter match," Earl said. "Everybody played real well. I think we surprised some people today."
In previous action, Kinstler swept at No. 1 singles, and Thigpen and Tran did the same at No. 1 doubles, but Laguna dropped a 10-8 nonleague match to host Dana Hills.
"Our girls played very well," Laguna Coach Aaron Talarico said of the Dana Hills match. "Lauren Thigpen and Heather Tran swept at No. 1 doubles against some very good Dana Hills doubles teams. I am very happy about that."
Taking the spotlight Saturday in a "seeded" race that had an 8:55 p.m. start, Laguna ran to an 11th-place finish at the Woodbridge Invitational.
The "seeded" race was made up of 19 of the top-caliber programs in all divisions throughout the state.
Jeremy Eaton led the charge for the Breakers with a personal-record time of 15:22, which earned him a 16th-place finish. Andrew Raub came up with a quick finish to place 26th in a time of 15:38.