Right-hander Teddy Stankiewicz allowed only one baserunner, on a sixth-inning single, to lead the Portland Sea Dogs to a 3-0 win over the Erie SeaWolves on Tuesday night before 6,189 at Hadlock Field.

The one-hit, complete-game shutout was easily the best outing for Stankiewicz (4-7), who needed only 96 pitches. He struck out a career-high seven.

Stankiewicz, who has had an up-and-down season, lowered his ERA to 4.81.

“He had unbelievable confidence in everything he threw,” catcher Jake Romanski said. “I could (call for) fastball, change-up or slider, and it would work – anything in any count. Everything was down in the zone.

“He was locating as well as I’ve seen anyone this year.”

Mauricio Dubon paced Portland with two doubles, two RBI and a run. Ryan Court also doubled in a run.

Stankiewicz retired the first 16 batters until one out in the sixth when Grayson Greiner grounded a single into center field. The Hadlock crowd responded with an ovation for Stankiewicz. He got out of the inning with two flyouts as he retired his final 11 batters.

“I’ve caught him the last three years,” Romanski said. “We knew Teddy could do that. That’s him right there. That’s Teddy.”

Stankiewicz, 22, arrived in Portland this season as Boston’s 20th-best prospect, according to Baseball America. He carried a 1.13 ERA through his first four starts – and in nine of his first 10 starts he allowed two earned runs or fewer. But he has also had some blowups (eight earned runs twice) and bouts of inconsistency.

“He’s a guy who is growing before our eyes,” Portland Manager Carlos Febles said. “He started out well, hit a bump in the road and was down, and now he’s getting up.

“Seems like he has more confidence now. Tonight was an example of that. That’s what we expect out of him – maybe not always a one-hitter, but to compete every start because he has the stuff.”

Stankiewicz politely declined to comment, rushing out of the clubhouse after learning a family member was hospitalized.

NOTES: Second baseman Yoan Moncada was initially in the lineup but did not play. Febles said he planned to give Moncada day off, but mistakenly penciled him in. … Dubon’s performance boosted his batting average to .318, and OPS to .832 … Portland (41-67) and Erie (44-65) are both in last place in their respective divisions in the Eastern League … Boston Celtics small forward Jae Crowder made an appearance at Hadlock Tuesday, signing autographs.