The improved control, the extra velocity and the biting breaking ball were all good things for Mariners right-hander Justin Dunn on Thursday.

Even better for Dunn was simply playing on Jackie Robinson Day.

“It was pretty cool to be able to honor him and play (and recognize) everything he’s done for this game,” Dunn said. “He inspired me as an African American in baseball. I wouldn’t be here without him — without all the hard things that he’s endured and he went through and his family went through. So to go out there and kind of leave it all out on the field like that it was, it was a great feeling.”

Dunn had one of the better starts of his young career to help the Mariners complete a doubleheader sweep of the Orioles at Baltimore’s Camden Yards. Both games of the doubleheader were seven innings in length.

Dunn allowed only one run — a solo homer to Freddy Galvis — on two hits with six strikeouts over five-plus innings in the Mariners’ 2-1 victory in Game 2. Mariners ace Marco Gonzales had a quality bounce-back start in Game 1 to help the Mariners to a 4-2 victory.

Most notable for Dunn: he walked just two batters on Thursday — with a tight strike zone, no less — eight days after allowing eight walks over 4 2/3 innings against the White Sox in his season debut.


Dunn acknowledged he was being too fine — trying to be too perfect with pitches on the edges of the plate — in that first start. On Thursday, he was determined to be aggressive. In his words, he attacked with a (censored) “screw-you” mentality against the Orioles hitters.

He threw first-pitch strikes to 15 of the 20 batters he faced.

He was pulled after walking the leadoff hitter, DJ Stewart, to open the sixth inning. Reliever Will Vest came in and got out of the inning, in part, after turning an unlikely 1-6 double play. He caught a sinking line drive right back to the mound off the bat of Anthony Santander, then turned and threw to shortstop J.P. Crawford to double up the base runner, Stewart, at second base.

Mitch Haniger, continuing his hot start to the season, homered in both games of the doubleheader, becoming the first Mariners’ leadoff hitter to ever do that.

In Game 2, his 412-foot homer off Orioles starter Bruce Zimmerman broke a 1-1 tie.

The homer was Haniger’s second of the day, and both came in the fifth inning. He hit a 436-foot blast that finally helped chase Orioles starter Matt Harvey in Game 1.

Haniger’s first blast was measured at 436 feet, the longest home run of the season for Seattle.


“I feel good,” Haniger said. “Still working on some things to find that right timing with my hands, but it’s been good so far. For me, my swing is always kind of a work in progress. I’m just trying to swing at good pitches, and I’m happy with how the last couple days have went and we’ve just got to keep building off that.”

Haniger has four homers in 13 games this season in his long-awaited return to the lineup.

“He’s a game-changer,” Crawford said. “I’m happy he’s healthy, that’s the main thing. He’s healthy, he’s ready to go. And not even (just) on the offensive side, he’s an absolute weapon out there in right field, too — covering tons of ground, making diving plays every other day. You can’t teach that type of ballplayer. I’m happy he’s healthy, and I’m happy he’s back in our lineup.”

Dylan Moore hit his first homer of the season off Zimmermann in the third inning of Game 2.

Working around another poor start in Game 1, Gonzales finally found his old form after the first inning.

Gonzales had been hit hard in his first two starts of the season, giving up 12 runs in 10-plus innings against the Giants and Twins, including five home runs.


He allowed another homer — a two-out, two-run shot run to Trey Mancini — in the first inning Thursday.

He settled down to retire 10 in a row during one stretch, and allowed only one base runner — a fifth-inning walk — in his final four innings.

“I have done this a lot of times before. Failed a lot of times before. And, you know, this is nothing new to me,” Gonzales said. “I wouldn’t be here if I hadn’t failed and learn from my mistakes a lot. You’re going to get the same guy every time out, and I’m going to keep putting in the work to get continue to get better.”

Gonzales (1-1) got the win when the Mariners rallied in the top of the sixth inning.

Jose Marmolejos walked to lead off the sixth. With two outs and two strikes, J.P. Crawford pulled a slider from lefty Tanner Scott just fair down the right-field line, scoring pinch runner Braden Bishop from second and Dylan Morris from first to give the Mariners a 4-2 lead.

After a slow start to the season, Crawford has eight hits in the past six games — none bigger than the go-ahead double in Game 1.

Keynan Middleton and Kendall Graveman each earned saves for the Mariners on Thursday. Manager Scott Servais was quick to note the success of the Seattle bullpen recently. Seattle relievers — Middleton, Gravemen, Vest and Rafael Montero — combined to allow just two hits and no walks in four scoreless innings Thursday.

The Mariners (8-5) took three of four from the Orioles in the series — after splitting their first doubleheader Tuesday — and finished their first road trip of the season with a 5-2 record. They head back to Seattle to begin a five-game homestand Friday night against Houston before welcoming in the Dodgers.

Game 1: Mariners 4, Orioles 2 (box score)
Game 2: Mariners 2, Orioles 1 (box score)