MONMOUTH — One big inning was all Monmouth Academy needed in its 14-0 Class C South quarterfinal victory over Lisbon on Wednesday.

The top-seeded Mustangs (16-1) scored 11 runs in the bottom of the second en route to a five-inning mercy rule win over the ninth-seeded Greyhounds (10-8).

Monmouth, the defending Class C state champion, will face either No. 5 Maranacook (11-5) or No. 4 Old Orchard Beach (8-8) in the semifinals on Saturday.

Monmouth’s Sammy Calder went three innings on the mound, allowing two hits and striking out two batters. He had three singles and three RBIs.

“It was just getting my foot down early, and hit the ball hard,” Calder said. “If I get ahead, there you go, just try to hit the ball hard.”

The second-inning scoring started when Carter O’Connell singled home Noah Schultz for a 1-0 lead, then, with the bases loaded, Kyle Palleschi grounded into a fielder’s choice, but the throw home went to the backstop and two more runs scored.

Luke Harmon added a two-run single for a 5-0 advantage. Jake Harmon scored on a pass ball, Calder’s single brought in Luke Harmon, and Schultz doubled home Calder and later scored on a passed ball to make the lead 9-0. Brandon Smith hit a two-run single to cap off the 11-run second inning.

“We put ourselves in a good situation when we only had one out and we started hitting the ball well,” Luke Harmon said. “When you start doing that, your team will rally around you. It carries over from at-bat to at-bat. You see a guy in front of you have a good hit, ‘It’s time for me to step up.’”

Calder said the Mustangs had a bitter taste in their mouth after the first inning when Luke Harmon doubled but was later tagged out at home on a double steal to end the inning.

“After the first inning, it kind of woke us a bit,” Calder said. “We went three-and-out; after that, we all got dialed in.”

Luke Harmon led the third off with a double and scored on a Calder single. The Mustangs added a run on a walk with the bases loaded, and Kyle Palleschi got hit by a pitch to bring a run to make it 14-0.

Luke Harmon, not known for his speed, ran around the bases a lot on Wednesday.

“I am not the quickest guy, I don’t have a great jump at all,” Luke Harmon. “I am not a guy stealing any bases.”

To keep Calder’s pitch count down so he’ll be available to pitch in the semifinals, he was relieved by Isaac Cote came in relief for Calder to start the third inning. Cote, only had thrown a handful of innings this season, allowed one hit and walked one in two innings of work.

“I told the kids my plan, if we could, ideally, to get out of here with everybody available Saturday,” Monmouth coach Eric PalIleschi said. “To put Sammy out there, we told him he had 40 pitches, and it was going to be Isaac.”