ERIE, Pa. — Luis Diaz was promoted to Double-A on Monday after Portland Sea Dogs starting pitcher Miguel Pena was suspended for 100 games.

Diaz took advantage of that opportunity Wednesday, putting together a masterful Double-A debut.

The 22-year-old Venezuelan allowed only one base runner in six dominant innings to lead Portland to a 5-1 win over the Erie SeaWolves as the Sea Dogs salvaged the final game of the series in front of 2,489 fans at Jerry Uht Park.

“Luis did a good job,” Portland Manager Billy McMillon said. “He pounded the strike zone and used minimal pitches to keep (Erie) off balance.”

Diaz’s performance made the 12-hour bus ride back to Portland a little easier after the Sea Dogs fell 8-6 earlier in the day in the completion of a game suspended Tuesday night.

Diaz was signed by the Boston Red Sox in 2008 and spent two seasons in the Dominican Summer League. He moved up to the Lowell Spinners in 2011 and Greenville in 2012. After splitting time between Greenville and Salem in 2013, Diaz started the current season in Salem and was 6-3 with a 3.33 ERA.

“I was trying to throw my fastball for a strike early in counts,” Diaz said. “I wanted to throw all of my pitches for strikes, and I’m excited we got the win.”

Diaz challenged hitters throughout the afternoon, needing just 53 pitches to get through six innings. The only hitter to reach base against Diaz was Jason Krizan, who drove a fastball down the right-field line in the fourth inning for his fourth home run of the season.

The Sea Dogs got to Erie starting pitcher Warwick Saupold in the top of the fourth. Sean Coyle and Stefan Welch drew walks before Keury De La Cruz lifted a single down the left-field line, just out of the reach of the left fielder, shortstop and third baseman.

Welch and Saupold were teammates for Australia in the World Baseball Classic.

David Chester, a 6-foot 5-inch, 270-pound first baseman who was promoted to Double-A last week, crushed an opposite-field grand slam to give Portland a 4-0 lead.

“It felt great to come through because there were situations early in the season that I didn’t come through for my team,” Chester said. “It was a huge win for us and saved the series. It also made the bus ride a lot easier to enjoy.

“My approach was to drive the ball deep into the outfield to bring a run in and keep it off the ground to avoid a double play.”

Deven Marrero hammered a ball deep to left field in the fifth inning for his third home run of the year to extend the Sea Dogs’ lead to 5-1.

Portland led Erie 2-0 with two runners on and nobody out when the suspended game resumed at 11:05 a.m.

The Sea Dogs couldn’t add to their lead, and then Erie got three runs in the bottom of the second against reliever Wilfredo Boscan with a bases-loaded walk to Dixon Machado, an RBI single by Jamie Johnson and a sacrifice fly by Krizan.

Boscan lasted 42/3 innings, trying to save a Portland bullpen that could be taxed this weekend with two makeup games against Altoona. He allowed six runs on eight hits.

Welch clubbed his fourth home run to cut Erie’s lead to 8-5 in the eighth. The Sea Dogs had one last chance in the ninth, loading the bases with nobody out, but they managed just one run on Welch’s sacrifice fly.