READING, Pa. — The Portland Sea Dogs haven’t slowed down since do-it-all second baseman Mookie Betts was promoted to Triple-A in early June. Derrik Gibson has helped make sure of that.

Gibson has stepped into Betts’ leadoff role and has continued to help the Sea Dogs get off to fast starts. He did it again Friday, setting the tone for a 12-2 win at Reading by reaching base five times and scoring three times.

“I’m trying to do what Mookie would do, I guess, just try to be patient and get us rolling,” said Gibson, who had two hits, walked twice and was hit by a pitch. “I’m just trying to be that spark plug. Anything I can do for these guys, I’ll do.”

The Sea Dogs (52-27) have barely missed a step without Betts. They were 38-19 before he left for Pawtucket and have gone 14-8 since.

“It just shows what kind of club we have here,” Gibson said. “We just fill in whenever somebody leaves. You want to play in the big leagues, and guys are gonna leave. There’s always the opportunity to step in somewhere, and I think we’ve done that collectively.”

What the Sea Dogs did best Friday was wait out the Fightin Phils pitchers, none of whom could find the strike zone consistently.

Perci Garner, who leads the league in walks allowed, walked Gibson to open the game, then walked Blake Swihart and Sean Coyle one out later. Gibson and Swihart eventually scored to give the Sea Dogs a 2-0 lead

Garner finished with a career-high eight walks in 31/3 innings. Fightin Phils pitchers combined for 13 walks; nine of those 13 batters scored.

“That’s our motto of the Red Sox,” said Gibson, “Be selectively aggressive, try to get a ball in the zone that you’re looking for, and I think we did a good job of that, not helping out their pitchers.”

Stefan Welch’s sacrifice fly and the first of designated hitter Keury De La Cruz’s five hits drove in first-inning runs.

De La Cruz and Peter Hissey had RBI singles in the third to make it 4-1.

The Phils (33-43), who have lost 10 straight, completely fell apart in the fourth with two errors, two wild pitches and a passed ball to go along with four walks – leading to four Portland runs and an 8-1 lead.

All of that overshadowed the work of Sea Dogs left-hander Brian Johnson, who won his fourth straight start and improved to 7-1.

Johnson’s control wasn’t quite as sharp as usual, but he allowed just one run over five innings despite walking four and allowing five hits. He struck out seven, one short of his season high.

Over four June starts, he is 4-0 with 22 strikeouts over 24 innings while allowing just three earned runs. His ERA is 10 Double-A starts is 1.67.

Johnson is five innings shy of qualifying for the league ERA lead and displacing teammate Henry Owens, who is the current leader at 2.25.

NOTES: Swihart reached base five times, on a single and four walks. … Betts entered the day still sharing the Eastern League batting lead at .355. Within the next week he’ll fall off the leaderboard due to not having enough plate appearances to qualify. Coyle is hitting .357 but doesn’t yet have enough plate appearances to qualify.