Merrimack catcher Katie Coolidge tags out Salem's Lily Gross before she crossed home plate in the fourth inning of Merrimack's 4-1 win on Friday. (Photo by Dan Doyon)

SALEM – With the third seed in the Division I tournament on the line, the Merrimack and Salem High School softball teams battled in a tied game through five innings of Friday’s regular season that would place the final piece of the postseason puzzle.

Merrimack then determined its own fate.

The Tomahawks scored the runs in the top of the sixth inning and pitcher Marissa Nelson held off Salem en route to a 4-1 victory over the Blue Devils.

“It’s very, very exciting,” Nelson said. “We treated this like a playoff game and we were just hyped the whole way here. This was the biggest win of our season and I’m really proud of them.”

Merrimack (15-3) will host either Bedford, Dover or Nashua South (all 6-12) as the 14th seed in Wednesday’s preliminary round. The official NHIAA tournament pairings will be released on Monday.

“They played the way they played all year,” Merrimack coach Steve Yabroudy said. “It’s defense first and then we scrap runs to get them across. It’s not always pretty, but we hit the ball pretty well today.”

Salem (14-4) heads into the tournament as the fourth seed and will likely host Exeter (8-10) on Wednesday.

Two-time defending Division I champion Londonderry (17-2) and Pinkerton Academy (16-2) received first-round byes as the top two seeds.

“Last year we were (No. 9) in the tournament and we’ve had so much growth,” Salem coach Mariah Tebo said. “We’re young; we only have three playing seniors. These girls have been amazing this season and I’m excited to see where they’ll go.”

Merrimack had nine hits against Salem pitcher Maddie Bellavia, which included a RBI single from Cameron Bellen in the top of the first inning to give Merrimack a 1-0 lead.

Nelson allowed only one hit through three innings before Salem had four hits in the fourth, but she escaped by only allowing an RBI fielder’s choice to Michaela Daley. Salem’s Lily Grace was thrown out at the plate on a relay throw from second baseman Olivia Burke to catcher Katie Coolidge.

The Tomahawks opened a cushion when Ashley Seneca led off the top of the sixth with a double. Olivia Burke and Allie Wyand followed with RBI singles and Nelson walked with the bases loaded to give Merrimack a 4-1 lead.

Nelson ran into more trouble in the bottom of the sixth when Bellavista, Caroline Case and Averie Bolduc all singled to load the bases. With two outs, Merrimack center fielder Bayliegh Robichaud chased down a line drive by Emilie Troisi.

Merrimack’s Bayliegh Robichaud (left) congratulates Katie Coolidge after she scored in the sixth inning of Friday’s 4-1 win over Salem. (Photo by Dan Doyon)

“(Nelson) has been incredible all year,” Yabroudy said. “She never takes herself out of the game. You saw how many hits were today and she’s still there working hard. I would say a couple of years ago it probably wouldn’t have been like that, but her mindset has matured and it’s been fun to watch.”

Nelson worked around nine hits and a walk with seven strikeouts.

“That’s probably the most anybody has hit off me this year, but it was just trusting my defense every time,” Nelson said. “I knew what they were capable of and what this team is capable of.”

The expectations for Merrimack may have increased, but the Tomahawks know first hand that they can’t take the first round lightly after losing to Spaulding last spring as the No. 6 seed.

“I just want to get past the first round because we lost last year,” Yabroudy said. “It’s one game at a time, but I feel pretty good.”