The Edward Little softball team waits for Chantel Ouellette to cross the plate after she hit a grand slam against Messalosnkee in the Class A North quarterfinals in Oakland on Wednesday. (Michael G. Seamans/Kennebec Journal)

OAKLAND — In a game full of opportunities on both sides of the diamond, Chantel Ouellette made the most of hers with one swing of the bat.

The sophomore pitcher clubbed a mammoth grand slam to left field, a no-doubt shot that broke a tie and lifted No. 5 Edward Little to an 8-4 win over fourth-ranked Messalonskee in the Class A North softball quarterfinals Wednesday afternoon at Veterans Field. The Eddies (10-7) will play the winner of Thursday’s other quarterfinal between Skowhegan and Bangor in the regional semifinals on Saturday.

Ouellette’s game-breaking home run was the first of her career — of any kind, at any level.

“It felt really good off my bat, and we needed something to get us going offensively,” Ouellette said. “With the bases loaded, I just needed contact, and it went.”

Edward Little coach Elaine Derosby couldn’t have been happier for Ouellette.

“She has the power,” Derosby said. “She’s hit for power a lot this year. On that pitch, it was in her perfect spot. It was in her wheelhouse. She’s a gamer.”

Through the first five innings Tuesday, nobody would have dared suggest a single swing of the bat would decide things.

Edward Little scored twice in the second to take the early lead. Messalonskee responded with a four-run third. The Eddies grabbed a run back in the fourth by taking advantage of three wild pitches from Eagles starter Danielle Hall.

Neither pitcher put a clean 1-2-3 inning in the scorebook as the two sides combined for 18 hits, 11 walks, 10 errors and four hit batters. A marathon that grinding was more befitting Boston’s annual 26.2-mile April tradition than a softball playoff game.

That said, once Ouellette delivered the grand slam — the fifth consecutive Edward Little batter to reach base to begin the top of the sixth — it felt like it was over.

“We just wanted to get that one big hit,” Ouellette said.

“It’s definitely hard, late in a game, to think you have to come back four runs to come get it,” said Messalonskee coach Samantha Moore, whose team finishes 9-8. “We stayed positive, though.”

The Eagles went just 2 for 16 on the day with runners in scoring position, loading the bases in the seventh with one out without scoring after going 1 for 5 in that situation during their four-run third.

That big third for Messalonskee was aided by six Edward Little errors, including two on a play that generated three runs from a Sarah Labbe single to center.

Ouellette did an admirable job of simply limiting the damage everywhere else during her complete-game effort in the circle. In the fifth, she snared a bullet off the bat of Taylor Bernier ticketed for center field and turned it into a double play.

“You just have to keep going to the next pitch,” Ouellette said. “I know I’ve got my teammates behind me that can make plays. I’ve just got to get ground balls.”

Edward Little wasn’t much better under pressure, going 2 for its first 12 with runners in scoring position. The Eddies finished 5 for 21, keeping Messalonskee within striking distance.

“That’s been our M.O. all year,” said Derosby, who admitted the win was a bit bittersweet with her husband Keith Derosby serving as the successful Messalonskee girls’ basketball coach of several of the Eagle softball players.

“We’re kind of young. At the plate, they come and go. We’ve got to try different things, we’ve got to be able to make them make plays.”

“We had our chances,” Moore said. “The girls were up and playing hard from inning one through seven. They played their hearts out and just got unlucky in some spots.”

Messalonskee first baseman Alyssa Genness can’t handle the poor throw to get Edward Little’s Abby Russell (3) out in the Class A North quarterfinal game in Oakland on Wednesday. (Michael G. Seamans/Kennebec Journal)Messalonskee pitcher Alyssa Genness (4) tries to play the bunt off the bat of Edward Little’s Jordan Cummings during the Class A North quarterfinal game in Oakland on Wednesday. (Michael G. Seamans/Kennebec Journal)Edward Little’s Jordan Cummings (14) knocks the ball free from the glove of Messalonskee High School pitcher Alyssa Genness (4) as she tries to apply the tag after a bunt during the Class A North quarterfinal game in Oakland on Wednesday. (Michael G. Seamans/Kennebec Journal)Edward Little’s Anna LeBlanc high-fives the first base coach after a hit against Messalonskee during the Class A North quarterfinal game in Oakland on Wednesday. (Michael G. Seamans/Kennebec Journal)