Los Angeles Loyola defeats Bellflower St. John Bosco, 28-14

Let me give some advice to future opponents of Los Angeles Loyola: Don’t mess with the Cubs’ secondary.

Bellflower St. John Bosco, loaded with outstanding receivers, was shut out in the first half Friday night and finished with 121 yards passing in a 28-14 loss to the unbeaten Cubs at L.A. Valley College.

Yes, call it an upset, because St. John Bosco (3-1) came in ranked No. 14 by The Times and Loyola (4-0) was ranked No. 21. But there was little doubt from start to finish which team was better.

And there was no doubt about identifying the best player on the field. That was Chaz Anderson, a senior receiver-cornerback for the Cubs who is committed to Boise State. He had touchdown receptions of 23 and 12 yards. He was part of a secondary that denied the big play except for a 44-yard touchdown reception by Bryce Treggs in the third quarter that Anderson barely missed knocking down.

“He’s a great football player,” St. John Bosco Coach Jason Negro said of Anderson. “We knew it coming in. When he had opportunities to make plays, he did.”

Another standout two-way player was junior Cameron Walker, a running back-cornerback. He had a 35-yard touchdown on a fumble return and scored on an eight-yard run with 7:14 left to clinch the victory after an 80-yard, 12-play drive.

Loyola went 3-7 last season in Coach Mike Christensen’s rookie year, finishing in last place in the Serra League. The six-time Southern Section champion Cubs are trying to regain their winning ways, and all signs indicate they are headed in the right direction.

“I’m feeling like fireworks are going off,” Anderson said. “It’s a great win because we showed the doubters what we’re capable of.”

No coach could have felt more satisfaction in the execution by his players than Christensen in the first half.

Players not directly involved in plays were fulfilling their roles, such as receivers blocking down field and running backs picking off rushers to protect quarterback Nick Cotton.

Loyola was near flawless in taking a 21-0 halftime lead.

“We played focus and didn’t beat ourselves and played a great defensive half,” Christensen said.

St. John Bosco threatened in the third quarter after cramps to Anderson and Walker left the Cubs turning to backups. Treggs’ touchdown, combined with a fumble return for a touchdown by Christian Wehrly, pulled the Braves to within 21-14.

But Loyola put together its long drive in the fourth quarter, with Anderson making two catches and Walker running hard in place of the injured Wyatt Bradford (ankle injury). Cotton finished 15 of 20 for 147 yards and two touchdowns.

What a night for high school football in Southern California. There were seven matchups involving teams ranked in the top 25. And Loyola showed it belongs in the conversation.

eric.sondheimer@latimes.com