Kennebunk is the only Class B team to beat Marshwood since 2017, winning last year’s regular-season game on Ryan Connors’ last-second field goal. Brianna Soukup/Staff Photographer

KENNEBUNK — Most weeks, the Kennebunk and Marshwood High football starters know they’ll probably be watching from the sidelines by the fourth quarter, another win safely secured.

This is not most weeks. At 6 p.m. Friday in South Berwick, the two dominant programs in Class B South renew what has arguably become the best, most competitive rivalry in Maine.

Marshwood (5-1) is the two-time defending Class B state champion. Its loss this season was at defending Class A champ Thornton Academy, 28-27.

“They’re that big obstacle in our way,” said Kennebunk senior guard/inside linebacker Ethan Roy. “It’s not that we hate them. It’s more just, they’re the team in our way. I think everyone here respects how good they are.”

Kennebunk (5-1) is the only Class B team to beat Marshwood in the past two-plus seasons. The Rams’ loss this year was to perennial Class A power Bonny Eagle, 42-21.

Since 2016, Kennebunk and Marshwood have played five times. The largest margin of victory has been six points, when Kennebunk won a 2016 South semifinal, 13-7. In that time, the teams’ overall records are nearly identical: Kennebunk is 34-5, Marshwood is 34-6.

“I mean, it’s probably the biggest rivalry I’ve been a part of for football,” said Marshwood senior captain Justin Bryant. “You get to play the whole game. I like that a lot better. It’s more fun. It’s more intense, you know?”

The major difference between the programs is that Marshwood has won four state championships in the past five years. Kennebunk was the regional champion in 2013 and 2016 but lost both years in the state final.

“They’ve got a run going and they’re the measuring stick. Definitely,” Kennebunk Coach Joe Rafferty said. “They’ve got the back-to-back state titles to prove it.”

After losing to Kennebunk in the regular season last year, Marshwood got its revenge with a 14-13 win over the Rams in the Class B South final. Ben McCanna/Staff Photographer

The Hawks also view Kennebunk as their gauge. In its five wins against Class B opponents, Marshwood has had a 249-10 scoring advantage. After a week five 56-7 win against Biddeford, Marshwood Coach Alex Rotsko was asked if his team was really as good as the lopsided margins indicated.

“I don’t know. We’ll find out when we play Kennebunk, I guess,” Rotsko said.

For both teams, Friday figures to be a rare chance to play a close game.

Since the start of the 2017 season, Marshwood’s 26 wins against Class B teams other than Kennebunk have been by an average of 37.6 points. Kennebunk’s average margin of victory against the rest of Class B is 32.8 points.

The cumulative score of the last three Marshwood-Kennebunk games? Marshwood 43, Kennebunk 42.

Kennebunk’s Ryan Connors, left and Marshwood’s John Valentine will likely match up again Friday night. Ben McCanna/Staff Photographer

All three have gone to the wire. Marshwood won at Kennebunk in 2017, 15-12, needing an interception in the end zone to secure the win. Last fall in the regular season, Kennebunk’s Ryan Connors hit a last-second 31-yard field goal for a 17-14 win, but Marshwood won the regional final, 14-13, at Waterhouse Field in Biddeford, the difference a blocked PAT and three fourth-quarter defensive stops.

“I just think we both have good personnel, obviously,” said Rotsko. “You have to have good players, and we’ve both had good players, and that’s probably the biggest thing.”

Marshwood is led by Bryant, a four-year starter at fullback and the vocal leader of the defense. He has scored 16 touchdowns this season. Senior John Valentine is a threat as a runner and a receiver. Senior Connor Caverly has played well in his first season at quarterback and has continued to excel as a defensive end. Wide receiver Cullen Casey has shown tremendous ball reaction and hands, as evidenced by his 11-catch effort against Thornton.

Kennebunk graduated most of its top skill position players from last season but seems to have reloaded. With first-year starter Tommy Lazos directing the triple-option offense, Connors and Jacob Sullivan have been highlighted as running and receiving threats. Sophomore fullback David York has been a consistent ground gainer.

But if recent history is an indicator, Friday night’s game will be low scoring.

“Both teams do a great job of preparing, and we both have played very good defensively,” Rafferty said.