Turnover Turns Tide for Poway : High school football: Titans strike early to score a 7-0 upset of Mt. Carmel in the Section 3-A semifinals.

That flush heard throughout Mira Mesa on Friday night was the sound of a dream going down the drain.

Poway used a bit of thievery and scored on the game’s second play to knock off third-seeded Mt. Carmel, 7-0, in front of about 6,000 at Mira Mesa.

Poway (10-3) will face tonight’s Orange Glen-Morse winner Saturday (4 p.m.) at San Diego Jack Murphy Stadium to determine the section’s 3-A champion.

It is the first title Poway has played for since 1963, when it lost the 1-A championship to Oceanside. The Titans were 2-8 last year, including a victory over Mt. Carmel.

The Sundevils (10-2-1), the Palomar League champion, had their nine-game winning streak snapped. Poway entered the playoffs as the Palomar League’s third team. Mt. Carmel had a 1-9 record last year.

The game’s two key plays involved Marlin Carey, the county’s third-leading rusher who gained 317 yards a week earlier against Castle Park.

Mt. Carmel elected to receive the opening kickoff. From the 16, Carey took the handoff. From there, it got fuzzy. Was the ball stripped out of his hands or did it pop out? Neither Carey, nor Poway’s Joe Enyeart, could say.

“I straightened him up, and when he tried to cut to the outside, the ball just popped up,” said Enyeart, a 5-8, 167-pound defensive back. “I just took it. It was instinct. I felt the ball and pulled it out.”

And then he ran toward the end zone, only to be stopped by quarterback Damian Dolin.

“I thought I had the TD,” Enyeart said. “I was hoping when he tackled me I was going to fall into the end zone.”

Instead, Russ Fouts took the ball in for the game’s only score. Matt Turner added the extra point and Poway had a 7-0 lead just 46 seconds into the game.

Carey, averaging more than 160 yards per game this season, rushed 13 times for 41. He suffered a knee injury early in the second quarter that affected his ability to cut. By game’s end, he was nothing more than a limping decoy.

“We told the kids all week we could shut them out with good defensive technique,” Poway Coach John Self said. “Last time we played them (a 14-7 loss), we tried to stop (receiver Charles Dejurnett and tight end Josh Eby) and Carey. They got only five yards passing, so we decided we had to stop Carey.

“It’s sweet when you get a chance to play a rival again. The underdog always has the edge.”