AUBURN — Mark Johnston took the mound in the second inning of Tuesday’s Class C South preliminary for No. 9 Old Orchard Beach having inherited a four-run deficit but seeing no reason to panic against No. 8 St. Dom’s.

“I just played my own game,” he said. “I didn’t let the score dictate how I played or if I should change anything.”

“I feel like we all did that, and I think it led to our success,” he added.

Johnston, a southpaw who started the game at catcher, allowed two runs in six innings and ended the game on a strikeout with the tying run at third as the Seagulls rallied from the four-run deficit then held on to defeat the Saints 7-6.

“No one started to hang their heads. We stayed focused through all seven (innings), even when it looked bad when they went up by four to start it,” Johnston said. “We always just kept fighting. Everyone contributed.”

OOB (7-10) advances to face unbeaten top seed Lisbon in the quarterfinals at 4 p.m. on Thursday. St. Dom’s ends its season at 7-10.

Trailing 7-5 to start the bottom of the seventh, the Saints got a single from Derek Wolverton then a double by Riley Volpe before pulling within one on Zack Pelletier’s RBI single.

With the tying and winning runs in scoring position, Johnston got a strikeout for the first out of the inning. The Saints then tried a suicide squeeze but failed to make contact. Catcher Peter Coleman chased Volpe down along the third base line and tagged him for the second out.

Pelletier advanced to third on the play to keep the tying run 90 feet away but was stranded there when Johnston ended the game by getting a swinging third strike.

OOB coach Tom LaChance said the Seagulls anticipated the Saints using the squeeze play in a big situation.

“We knew exactly what was coming and what pitch,” LaChance said. “I’ve coached against (St.Dom’s coach) Bob (Blackman) for 16 seasons, and you kind of know the tendencies of when he’s got something going on. We had worked 25 minutes in practice just on that.”

Blackman declined comment after the game.

St. Dom’s took a 4-0 lead without a single hit in the bottom of the first.

Old Orchard Beach starter Sean Pratt struggled with the mound and with his control and issued five walks, including four consecutively with two outs. Matt Doody replaced him and allowed a bases-loaded walk and a wild pitch to send the final two runs home before getting the ninth batter of the inning to fly to center field for the final out.

Blackman lifted his starter, Volpe after one inning, but a pair of one-out walks by reliever Wolverton came back to bite the Saints in the third. RBI singles by Doody and Isaac LaChance (two hits) off reliever Hunter Hughes and a delayed double-steal that scored Doody pulled the Seagulls to within 4-3 briefly.

After facing the minimum three batters in the second, Johnston surrendered a walk and singles by Volpe and Ben Gosselin in the bottom of the third to set up Mike Ciley’s RBI single that made it 5-3. The Saints could have added to the margin but Johnston picked off a runner at first, then tagged out another runner at the plate after uncorking a pitch to the backstop.

St. Dom’s lost another run in the fourth when a runner who scored from third on a dropped third strike was ruled out due to batter’s obstruction.

The runner at third, who broke for home after the OOB catcher threw to first for the putout, was initially ruled safe. But LaChance protested and, after a conference of the umpires, the call was reversed because the batter interfered with Coleman trying to make the tag after the throw back from first.

St. Dom’s had a couple of other chances to add to the lead, but left the bases loaded in the fifth and had a runner doubled up at first on a line drive to second in the sixth.

OOB tied it in the fifth after a walk and the fourth of St. Dom’s five errors set up Rudy Mago’s two-run pinch hit single.

“That was huge,” Johnston said. “That just shows how big our dugout is. We’re pretty deep.”

“Last Thursday at practice, we were in a rundown drill and (Mago) turned around, took a ball in the nose and got eight stitches and his eye closed,” LeChance said. “Today is his first day back.”

The Seagulls took the lead with an unearned run off Volpe after he returned for the sixth inning. Gavin Sperlich’s one-out single to center scored Johnston to make it 6-5. They added an insurance run off Wolverton in the seventh when, with runners at the corners, Brad Howle took off from first and induced a balk that scored LaChance.