Coming back from Tommy John surgery is supposed to be a grind, and right-handed pitcher Jacob Dahlstrand will assure you it is.

“I’m slowly climbing back up,” he said. “Obviously, I’m going to go through ups and downs.

Saturday night was an up. Even though Dahlstrand said he did not feel great during his Double-A debut, he allowed only three over six innings, helping the Sea Dogs to a 7-3 win over the New Hampshire Fisher Cats at Hadlock Field.

Portland’s offense supplied plenty of support with 12 hits, including three apiece from Mauricio Dubon and Cole Sturgeon and Cody Decker’s solo home run and double.

Yoan Moncada went 1 for 2 with two walks. One of Moncada’s walks came with the bases loaded, as pitchers are being careful with the hard-hitting prospect. Since the All-Star break, Moncada has walked six times in 14 plate appearances.

“He’s been able to lay off bad pitches,” Sea Dogs Manager Carlos Febles said. “Pitchers don’t want to give in, but he’s not going out of the zone to hit.”

Dahlstrand, 24, was making his fifth start this season, his first with Portland. He allowed three runs (two earned), along with two walks and two strikeouts.

Dahlstrand, a right-hander, was a 10th-round draft pick out of high school in 2010. He moved slowly through the system, but broke through in 2014 with a combined 2.90 ERA in Greenville and Salem. In 2015, he cruised through three starts for Salem (0.95 ERA) but was injured in the fourth start.

After a long rehab, Dahlstrand returned to the mound June 25 in the rookie Gulf Coast League. He made two starts there and two in Lowell before joining the Sea Dogs.

“We’re just building him back up,” said Sea Dogs pitching coach Kevin Walker, who knows a little bit about the process, having undergone Tommy John surgery in 2001.

“This is just another step in the process.”

Using a 90-92 mph fastball, with a curve, slider and change-up, Dahlstrand needed only 77 pitches (46 strikes). He gave up a first-inning single, then picked off the runner. In the fifth, he issued a walk, and Derrick Loveless followed with a two-run homer to right-center. An error led to a run on a sacrifice fly.

“I didn’t have my best stuff, but I pitched through it,” Dahlstrand said.

Reliever Williams Jerez threw two hitless innings and Luis Ysla pitched a 1-2-3 ninth.

NOTES: Red Sox President Dave Dombrowski was in attendance, watching from the box seats behind home plate. … The announced attendance was a sellout of 7,368. … The Sea Dogs wore light blue jerseys with a cartoon figure of Slugger the mascot on the front. After the game, the jerseys were raffled off to benefit the Muscular Dystrophy Association. … Decker’s homer was his sixth in 25 games with the Sea Dogs. He’s tied for second on the team with Benintendi. Nate Freiman has eight homers. … In Triple-A Pawtucket, former Sea Dogs lefty Henry Owens took a no-hitter into the eighth inning before giving up an infield single with two outs. Owens walked two and hit two.

Kevin Thomas can be reached at 791-6411 or:

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