PORTLAND — Somehow, Mike MacDonald missed seeing the enormous double rainbow that stretched above the Portland Expo Tuesday night.

It might have been the only blemish on an otherwise splendid debut for the first Mainer to play at Hadlock Field wearing a Sea Dogs uniform.

A native of Camden pitching in his ninth season as a professional, MacDonald tossed seven shutout innings to lead the Sea Dogs to a 7-0 Eastern League baseball victory over the Reading Phillies before an announced crowd of 5,008.

“I saw the lightning in the background,” MacDonald said. “But I didn’t get a chance to see the rainbow.”

Blame it on the one significant threat Reading posed to MacDonald, loading the bases on three consecutive one-out hits in the fifth as strong winds swirled, raindrops fell and the ground crew gathered to cover the infield with a tarp if a nearby storm system arrived.

MacDonald induced a softly-hit ground ball to the hole, and shortstop Derrik Gibson teamed with second baseman Ryan Dent to turn a double play that made the game a legal 41/2 innings with the home team leading 3-0.

“That was an impressive turn,” Sea Dogs catcher Dan Butler said. “I think that’s what saved the game for us there.”

In the other eight innings, MacDonald and Brock Huntzinger, who retired the last six Phillies in order, faced only one batter over the minimum. MacDonald set down the first eight batters, struck out two, never faced a three-ball count and threw 50 of his 72 pitches for strikes.

“He’s a guy who knows how to pitch,” said Sea Dogs Manager Kevin Boles, who had seen MacDonald throw to only five batters in his Sea Dogs debut in Trenton on July 8 before a hamstring injury landed him on the disabled list.

“The guys took care of the baseball, but it’s a credit to MacDonald because he maintained a consistent tempo and pace of the game and kept the defense involved.”

The victory also marked the 100th as a Sea Dogs manager for Boles, who was also treated to the first Double-A home run by Jackie Bradley Jr., and six stolen bases to tie a franchise record last achieved in 2002.

Bradley and Jeremy Hazelbaker (3 for 3 with two walks and two doubles) worked a double steal off Reading starter Julio Rodriguez (5-4). Hazelbaker, Bryce Brentz and Peter Hissey (twice) also stole.

“I thought our guys picked some very good counts to go on,” Boles said. “I liked the aggressiveness whether it was on the mound or on the base paths.”

The Sea Dogs staked MacDonald to a 3-0 lead in the first with Bradley’s home run to left-center, an RBI double by Marquez Smith and a pair of infield groundouts.

“I was looking for a fastball (on a 3-and-1 count) and saw early on that he was leaving ’em up,” said Bradley, who hit four homers over parts of two seasons in Class A before joining the Sea Dogs.

They padded it with runs in the fifth through seventh, aided by two of those six thefts. Hazelbaker stole second after a leadoff walk in the fifth, advanced on a deep fly to right and scored on Brentz’s single up the middle to make it 4-0.

Another leadoff walk in the sixth, to Hissey, resulted in another run after he stole second and third before scoring on Dent’s infield grounder.

The first of Hazelbaker’s doubles banged off the wall in right in the seventh and led to Brentz’s sacrifice fly for a 6-0 lead. Hissey’s two-out RBI single scored Smith to make it 7-0.

Not a bad way for the former Camden Little Leaguer, who once sat in the stands and cheered for the then-teal-colored Sea Dogs, to make his Hadlock debut as a member of the Red Sox organization.

“I’m very fortunate and very lucky to have the opportunity,” MacDonald said. “Definitely, I like this one a lot better than the last (start).”

NOTES: To make room for MacDonald on the roster, infielder Nick Natoli was sent to Class A Greenville.

Natoli appeared in 24 games with the Sea Dogs, mostly at third and second base, and batted .151.

“I have to give a big thanks to the training staff here,” MacDonald said. “They did a great job of getting me ready to go.” …

Old friend Stephen Fife made his big-league debut for the Dodgers Tuesday night in place of Chad Billingsley, who went on the disabled list with right elbow inflammation.

Fife, 25, was 7-5, 4.53 ERA in 18 starts for Triple-A Albuquerque but 4-1, 2.78 over his most recent eight starts. He pitched for the Sea Dogs in 2010 and 2011 before being sent to the Dodgers last July as part of a three-team trade involving Seattle and Erik Bedard. …

The Reading staff includes old friends Dusty Wathan (manager) and Frank Cacciatore (hitting coach). Wathan was a catcher for the 2001 Sea Dogs and Cacciatore managed the 1999 club.

Unfortunately, Cacciatore has a touch of pneumonia and did not make the trip but plans to meet the Phillies in Trenton.

Staff Writer Glenn Jordan can be contacted at 791-6425 or at: gjordan@pressherald.com

Twitter: GlennJordanPPH