STOCKTON — Tyler Scharnow is making up for lost time.

And the rest of the Valley Oak League is taking notice.

The oft-injured senior, hampered by various ailments over his first three varsity seasons at Weston Ranch, led the Cougars to a 3-1 upset of Sierra despite six errors committed behind him in a VOL makeup game Monday.

Or was it an upset?

While its 5-8 overall record (2-3 in league) won’t turn any heads, Weston Ranch is proving to be a different team with its ace on the mound.

On March 30, Scharnow pitched the Cougars’ 4-1 stunner against 2011 Sac-Joaquin Section playoff finalist Manteca. The following week, he spearheaded a near-upset of reigning league and SJS Division IV champion Oakdale.

 “I don’t know what it is, but it’s definitely different,” Scharnow said. “I just go up there and try to throw strikes. My hope is to get groundball outs — I don’t really go after the K’s.”

He had plenty of K’s on Monday, several coming in key situations. Scharnow struck out 12, walked two and hit one in a three-hit gem. Sophomore Jake Pruitt accounted for two of Sierra’s knocks.

Sierra (2-3, 10-5) had five batters reach in the first two innings — three on errors, and two on walks both issued to No. 1 hitter Dakota Conners. All were left stranded. Overall, Scharnow fired four inning-ending strikeouts with runners in scoring position.

 “He’s pretty good,” said Sierra coach Jack Thomson, who got his first look at Scharnow Monday. “He was the difference of the game.

“To give up one run (despite the errors), he did a heck of a job. I thought Mark (Crain) pitched good enough for us to win, but (Scharnow) was the difference.”

Crain wasn’t too shabby himself for Sierra, as he fanned eight while yielding five hits and two unearned runs.

The Cougars scored first in the fourth inning.

Jared Ferrari belted a two-out double to left-center field and was driven in by Marcus Vega-Tatum’s single to right.

Sierra scratched across the equalizer in the sixth, also with two outs. Joseph Collett reached on a two-base throwing error. Pinch-runner Makana Ward plated the Timberwolves’ lone run after Jason Angelo was hit by a pitch and Rodrigo Contreras reached on another infield error.

Weston Ranch made up for the defensive miscues in the bottom half of the sixth. Cristian Vazquez drew a one-out walk to start the game-winning rally. Ferrari then reached on an error, and Vega-Tatum smacked a groundball single to right to load the bases.

Pinch-runner David Perez and Ferrari eventually scored on wild pitches. Crain stopped the bleeding with two strikeouts.

“I know had our issues defensively today, but on offense I’ve got a lot of faith in these guys up and down the lineup,” Scharnow said.

Monday’s win was only the second for Weston Ranch against Sierra since its inaugural varsity campaign in 2005. The first came on May 2, 2006 when the Cougars battled back from a 10-1 deficit for a wild 17-16 victory.

The back end of the two-game series is rescheduled for April 24 at Sierra, but before the rematch both clubs have interesting challenges ahead of them with their aces each logging seven innings on Monday.

Sierra begins its two-game set with Oakdale at home Wednesday while Weston Ranch hosts Kimball.

“We’ll see how Tyler feels on Friday,” said Weston Ranch Ron Wayman. “These next two weeks are huge for us, so it will be a little tricky.