Junior Tyler Lonestar was impressive on the mound and the offense scored in five of six trips to the plate as De La Salle topped Serra 9-6 on Thursday afternoon.
Lonestar, making his first start of the season, struck out seven and allowed two runs in 4 1/3 innings as the Spartans improved to 2-1 on the season.
The loss dropped the Padres to 4-2.
De La Salle wasted little time getting to Serra starter Matt Blais as the Spartans struck for three in the first.
Blais, a UC Davis commit, struggled from the on-set as he hit the Spartans lead-off man then surrendered a double to Chris Williams. Junior Michael McAdoo then drove in the first run of the game with an RBI groundout. Outfielder Ben Polshuk - a Cal Poly commit - followed with an RBI single and Austin Dondanville drove in the third run via a safety squeeze.
Having been spotted an early lead, Lonestar went to work on the Padres hitters. The 6-foot-1 pitcher was in the mid-80's with his fastball and had an effective curveball as well.
Lonestar was perfect through three innings, but Serra finally got to him in the fourth when seniors Nolan Dempsey and John Murray doubled and hit a sacrifice fly respectively.
The Spartans then broke the game open and took a 7-1 lead in the bottom of the fourth with a trio of runs, highlighted by Miles Coston's RBI single.
Serra's major offensive highlight came in the top of the seventh when right fielder Neil Sterling, a Utah commit, blasted a three-run home run to right field.
However, by the time Sterling's blast brought the Padres within three, there was one out left and the Spartans had all but wrapped up the victory.