BILLERICA  — Staring down a potential upset, Billerica coach Duane Sigsbury turned to his best player. Steven Gentile delivered.

Gentile rushed for the go-ahead touchdown and game-winning two-point conversion as No. 2 Billerica held off an upset bid from No. 15 Plymouth South and came away with a 29-27 overtime victory in the opening round of the MIAA football state tournament on Friday night.

Billerica (8-1) will host No. 10 Westfield in the Division 3 quarterfinals next week.

“I knew coming into the game we were going to have to run the ball down their throat. That was what we worked on in practice all week,” Gentile said. “Before overtime I was told we were just going to run me so I gave it everything I had since it’s the playoffs.”

Gentile (20 carries, 126 rushing yards) was responsible for all four Billerica scores on the night, with three of those on the ground.

With the score knotted at 14 at the start of the fourth quarter, Sigsbury turned to Gentile’s talents as a passer for just the fourth time on the night. The junior delivered with a 21-yard touchdown pass to Noah Canada to put the hosts up 21-14.

Plymouth South responded. A 61-yard rush from Gio Lynch-Ruberio on second and long set up a one-yard touchdown rush by Casious Johnson (20 carries, 96 yards, touchdown) that evened the game at 21. After a Billerica three and out, Plymouth South (5-4) looked poised for an opportunity to win the game at the buzzer but time expired as the Panthers tried to call their last timeout at the Billerica 22, sending the game to overtime.

In the extra frame, Sigsbury turned to Gentile, who rushed for a five-yard touchdown and then a successful two-point rush to give Billerica a 29-21 lead. A one-yard touchdown run by Johnson brought the Panthers back within two, but the Indians stuffed Plymouth South’s two-point try to send the home fans into celebration.

“You’re going to turn to your best player. We’re very good up front and pounded it right in there,” Sigsbury said. “I think we showed our resilience tonight. When we’re healthy we’re as good as anybody.”

The first half went according to plan for Plymouth South as it controlled possession for most of the first 24 minutes.

The Panthers struck first when Justin LaChane capped off a seven-play opening drive with an eight-yard touchdown run. Plymouth South had a chance to stretch its lead on its following drive, but Canada ripped the ball away from Johnson to force a turnover.

Billerica capitalized on the change in possession as Gentile broke free for a 28-yard touchdown to even the score, 7-7, going into halftime.