BUCKFIELD — The Richmond-Buckfield softball rivalry has gone on for years, with the Bucks owning the series, then the Bobcats, and state championship plaques displayed in trophy cases throughout both high schools.

On Friday, in a classic Class D South semifinal, third-seeded Richmond rallied from a three-run sixth-inning deficit, then watched as the No. 2 Bucks battled back to force extra innings, before the Bobcats scored three unearned runs in the 10th inning for an 11-8 victory.

Richmond (13-3) returns to the Class D South regional final after a one-year hiatus —  thanks last year to Buckfield — and plays Tuesday at 3:30 p.m. at Saint Joseph’s College in Standish.

“Buckfield is awesome, but we tried to play the extra innings like it was 0-0, and we were able to do that,” Richmond coach Tony Martin said. “We got some timely hits. We made a few mistakes, they made a few mistakes. That was an amazing game right there.”

Through five innings it appeared the Bucks were on their way to a fourth straight victory over their rivals, having swept three regular-season contests. Richmond trailed 4-1 in the sixth, but with the bases loaded and two outs, the Bobcats scored seven runs, taking advantage of two Buckfield errors and receiving RBI hits from Nicole Tribbet, Caitlin Kendrick and Bryannah Shea for an 8-4 lead.

Buckfield, however, wasn’t finished. The hosts chipped away with two runs in the sixth on a two-run double by Cara Merrill, and tied the game in the seventh when Maggie Bragg slapped a two-out RBI single to right-center field.

“They don’t give up,” Buckfield coach Sandy Albert said. “When we played them earlier in the year, we were down 5-0 and we came back and won by three runs. I thought we had it. We had some opportunities, runners on second and third, and we were hoping to just slap the ball somewhere. This is tough.”

Richmond had a chance in the eighth as Tribbet singled, moved to second on a Merrill wild pitch before stealing third. But Merrill stranded the Bobcat base runner.

Buckfield’s (13-3) Paige Fogg doubled to open the ninth but was stranded at third as Kendrick retired three straight hitters.

In the 10th, Richmond received the break it needed, as a two-out error kept the inning alive. Shea gave the Bobcats the lead with a single. Brown slapped an RBI single to right field, and Hannah Moholland hustled to first on a bunt as Shea scored for an 11-8 Richmond lead.

“We have a funny superstition where we had the lead three times and they came back and got us,” said Brown, who was 3-for-5. “Today, they had the lead and we came back and beat them. All these girls have a big fighting spirit and we don’t give up. We just keep going.”

Early in the game, a throwing error by Brown from her center field spot allowed the first Buckfield run to score.

Brown made up for the miscue with several solid plays, including hauling in a sinking liner in the 10th and firing to first for a game-ending double play.

“If you make a mistake, you have to forget about it because another ball is coming at you,” Martin said. “You make an error, you have to get it out of your mind and keep digging. Our kids are amazing.”

“I knew if I kept my head down that I would just keep getting frustrated and make it worse. I put my heart and soul into running those balls down,” Brown said.

Trailing 2-0 in the fifth, Richmond drew within a run against Merrill when Kendrick ripped a single to plate Leah Wescott. But Buckfield threw out Tribbet at third on the play to maintain the lead.

The Bucks made it a 4-1 contest in the bottom of the fifth, but Richmond’s comeback began in the sixth.

Albert loses six players from her talented senior class, making Friday’s loss even more difficult.

“I thought it would be a good game, and you can’t give away anything to Richmond,” Albert said. “It is tough to lose in extra innings at home. It is tough to beat a good team four times. We just got the short end of it today. I feel bad for our seniors who gave everything to this program.”

Bragg paced the Bucks with three hits, two runs scored and three stolen bases, while Merrill added a pair of hits. Merrill had two stints on the mound, pitching a combined 8 1/3 innings (14 hits, 11 runs, six earned, one walk, three hit batters). Julia Dow tossed 1 2/3 frames (two hits).

Kendrick went the distance for Richmond, allowing 10 hits, four walks and two hit batters. She struck out eight.

Tribbet and Shea joined Brown with three hits each, while Kendrick, Bryanne Lancaster and Moholland added two hits apiece.