Down by eight points at halftime, Justin-Siena’s football team kicked it into high gear during the final 24 minutes of Thursday night’s home game against Piedmont to come out on top 44-27.

The Braves scored three touchdowns and a safety in the second half — and held the Highlanders scoreless — to nab their third straight win to open the season.

“It’s high school football,” Justin-Siena head coach Rich Cotruvo said. “It’s nothing else than momentum. We challenged our team at halftime. To their credit, they stepped it up and what a great half it was. They showed up in the first half and we showed up in the second.

“This is great momentum for us. We’re off to a great start.”

Cotruvo added that he only has two returning players from last year’s offense and three on defense — and to be 3-0 so far is a proud moment.

“That was an outstanding half of football,” Cotruvo told his team after its win. “I couldn’t be prouder of an effort. That second half — that’s Justin’s team.”

The Braves marched out of the locker room after the half to put eight points on the board within two minutes. Garrett Wright ran for his lone touchdown on a 56-yard rush and sophomore quarterback Kevin Reinell’s 2-point conversion pass to Chris Meyer was good to tie the score at 27-27.

Piedmont had to punt on its next possession and Justin-Siena made its way upfield to the 1-yard line. Stephen Shafer ran it in to give the Braves their second lead of the game at 35-27 — the first coming in the second quarter at 19-14.

Shafer led the Braves in rushing with 83 yards while Wright picked up 72.

Two and a half minutes into the final quarter, Justin’s Anthony Principe sacked Highlanders relief quarterback Will Conn for a safety and two more points. It was Principe’s second sack of the half.

Stephen Shafer scored his second touchdown on a 30-yard run with 8:23 left in the third quarter and Adam Eberwein’s PAT was good to complete the Braves’ scoring rampage.

But things didn’t start off so hot for the Braves. Actually, they were ice cold.

Piedmont’s Brendan Newland returned the opening kickoff 85 yards for a touchdown just 17 seconds into the first quarter. Jordan Remer’s PAT was good and the Highlanders had a 7-0 lead. The cushion jumped to 14-0 after Alexander Menke’s 65-yard pass to Newland was good and another PAT cleared the goalpost.

Reinell notched one of his own 65-yard passes to Meyer to put the Braves on the board and then completed a 10-yarder to Meyer with less than a minute left in the half to come within one point after Eberwein’s second PAT went wide.

On the night, Reinell threw for 207 yards on 13-of-22 passing with three touchdowns, though he was picked three times. “Kevin was absolutely magnificent in the second half,” Cotruvo said. “He really stepped up.”

Reinell was 6-for-6 in the second half without any interceptions. Meyer was his main go-to guy, collecting 95 yards while Wright added 68 and Alex Sanchez chipped in 44.

Justin-Siena managed one more touchdown in the first half, which came off a 56-yard pass from Reinell to Wright with 10:59 left in the second quarter. That gave the Braves a 19-14 lead, but it only lasted 57 seconds.

Menke connected with Newland for a 64-yard touchdown to go up 20-19. Then with :58.1 left in the second quarter, Peter Modera ran it into the end zone for a 5-yard rush to end the Highlanders’ scoring.

Justin-Siena (3-0 overall) plays at San Rafael for its first Marin County Athletic League game on Sept. 29 at 7:30 p.m.