COVINGTON — Coaches often talk about how one swing can change the momentum of a game.

Kimberly Nilsson changed a game with one swing Friday — and not only the momentum, but the outcome.

The Archbishop Hannan senior shortshop lined a home run to left field in the bottom of the fourth inning to break a scoreless tie in a Class 1A regional softball playoff game against Opelousas Catholic. The blast also helped Hannan shake from what appeared to be early nerves. From that point, the Hawks swung the bat with authority and purpose.

They finished with a 5-0 victory at Coquille Sports Complex and moved one step closer to earning their third consecutive state championship. Hannan improved to 21-8, while Opelousas Catholic closes 16-14.

Opelousas Catholic seemed to have the upper hand through 3.1 innings, as the Vikings had six hits to only one hit for Hannan. Opelousas Catholic stranded six base runners during that stretch, however, and that left the door open for Hannan to make its move.

Nilsson provided the spark with her blast with one out in the bottom of the fourth. She said the pitch she drove was a numbers-high fastball that didn’t have much movement coming to the plate. She said the homer seemed to excite her team.

“It was sort of a power starter, a surge,” she said. “Once we get our momentum going, it seems like we keep ripping off hits. It’s just ‘boom, boom, boom.’ ”

The Hawks tacked on a run in the fifth when Bailey Tuminello, who went 3-for-3, led off with a single to left. Carley Eshleman also singled in the inning and Lindsay Osbon later scored on Brooke Laigast’s double down the left-field line.

Hannan followed in the sixth with hits by Nilsson, Sydney Finch, Sydney Williams and Tuminello to widen its lead to 5-0. Williams had an RBI in the inning, and Tuminello, a sophomore, knocked in two runs with her third hit.

Tuminello said Nilsson’s homer really broke her team out of its early funk.

“This was the biggest crowd we’ve had all year, and they really helped us out with all the cheering,” Tuminello said. “That got us to realize, ‘Oh my gosh. We’ve got this.’ We got pumped up with them, and the adrenaline started flowing.”

Five runs was more than enough for Hannan’s senior pitcher Maddi Shelton (19-8). She threw a complete game and allowed six hits, all singles. She struck out five and didn’t allow a walk.

Hannan coach Becky Lambert said it took a while for her team to catch up to the speed of Opelousas Catholic starter Molly Fontenot.

“We knew it was probably going to be a little bit of a pitcher’s duel for a while,” Lambert said. “So concern? No. I was confident in our kids. Even if they had gone up a run, it wouldn’t have shut us down. With our seniors, we’ve always been able to get something back when we give something up.”

Opelousas Catholic coach Stephen Wren said his team played well but squandered opportunities in the early innings.

“We let too much pass us by,” he said. “I think if we score (early,) it’s a different game. But yes, once they hit the home run, they got their timing down on (Fontenot) and they started hitting her pretty good. That’s a good team Hannan has. I knew they’d end up hitting the ball. But I’m proud of my girls. They played hard.”

Fifth-seeded Hannan advanced to the state tournament at Frasch Park in Sulphur. They will play fourth-seeded Central Catholic, which was a 2-1 winner over Ouachita Christian in a regional game. The Hannan-Ouachita quarterfinal is scheduled for April 26.