DANVERS — What Mike Yarin may lack in experience, the first-year quarterback makes up for with innate athletic ability and poise beyond his years.

Yarin showcased those attributes in impressive fashion Saturday afternoon, leading eighth-ranked St. John’s Prep in a decisive Catholic Conference upset of fourth-ranked BC High, 35-17, in Danvers.

The junior ran 15 times for 75 yards and two touchdowns, adding two more scores through the air on 13-of-18 passing for 173 yards.

“The kid is a Division 1 athlete,’’ coach Brian St. Pierre said of Yarin, who made a verbal commitment to the University of Connecticut for baseball. “You saw a lot of that Division 1 mentality and competitiveness on display. Everything we throw at him, he just says ‘Give me more Coach’ and I’m happy to do that.’’

“He’s a good quarterback,’’ said BC High coach Jon Bartlett. “You have to give him credit. Their offensive line did a nice job against us today.’’

BC High (4-1, 1-1) coughed it up on the final play of the opening quarter.

Running to his right, quarterback Connor Cady found himself on the receiving end of a jarring hit. He fumbled the ball directly into the hands of Prep senior Brian Barrett, who returned it 77 yards for the game’s first score.

“Turnovers against a good team in a big game are never going to help,’’ Bartlett said.

BC High took a 10-7 lead when standout running back Danny Abraham, who rushed nine times for 79 yards but did not touch the ball in the second half, scored on a 50-yard touchdown run. Jarod Mockus converted a 32-yard field goal on BC High’s ensuing possession for the Eagles’ only lead of the game.

That’s when Yarin began cooking.

Operating from the shotgun at the BC High 2, Yarin pounded it in for the score, giving Prep the lead, 14-10, with just 1:12 remaining in the first half.

Less than a minute later, senior wideout/defensive back Hayden Rockett intercepted a Cady pass attempt and returned it 43 yards deep into BC High territory.

Rockett (eight catches, 75 yards) continued his impressive performance, slithering behind the defense and catching Yarin’s 27-yard strike in the end zone, giving Prep a 21-10 lead with five seconds left before halftime.

“[Hayden] is awesome,’’ said Yarin. “You see the plays where I throw balls at his feet and he makes the catch somehow.’’

Prep (4-2, 3-0) opened the second half with an 11-play, 70-yard touchdown drive that took 7 minutes 26 seconds and extended its lead to 28-10. The capper was Yarin’s 13-yard TD keeper.

“Last year we were up at the half,’’ Yarin said. “We were killing them and they ended up coming back, so the whole halftime we were saying ‘It’s not over’. We just kept our foot on the pedal.’’

Cady connected with junior Bobby DeMeo on an explosive 86-yard touchdown late in the third.

But Yarin put the game on ice with five minutes left in the fourth with his 35-yard TD strike to Michael Galatis.

“We knew everyone thought this game was going to go the other way and we felt differently about it,’’ St. Pierre said. “You want to be in big games like this. When you come to St. John’s Prep, every game is somebody’s Super Bowl and every game is a playoff game. It’s probably not good for my blood pressure, but it’s fun.’’

Owen Pence can be reached at owen.pence@globe.com.