BALTIMORE -- The stretch of June littered with off-days is over for the Orioles. After four idle dates over the previous 18 days -- including both Monday and Thursday this week -- Baltimore returned to Camden Yards on Friday night to open a nine-game homestand, beginning a run of 16 games in 17 days to close out the first half of the season and head into the All-Star break.

This wasn’t the way the O’s wanted to start such a stretch -- with their most lopsided loss of the season thus far.

A rare short night for right-hander Kyle Gibson and a quiet night by the offense sent Baltimore to a 13-1 loss in the series opener vs. Seattle. While Gibson allowed five runs in three innings (the briefest of his 16 outings in his first season with the Orioles), Mariners righty Logan Gilbert gave up only two hits over seven dominant frames.

“That was pretty ugly. Not our night,” manager Brandon Hyde said. “Let it go and come back tomorrow ready to play.”

Baltimore’s lone run came via a solo homer by Anthony Santander off Gilbert in the seventh, which ended a run of 15 consecutive batters retired by the Seattle starter. The only other O’s hits on the night were singles by Austin Hays (in the second) and Ryan McKenna (eighth).

In order to keep pace with Gilbert, Gibson needed a near-perfect outing. Instead, the 35-year-old labored during the second and third, throwing 35 and 34 pitches in those innings, respectively. He had already reached 86 pitches by the time Hyde decided to turn the ball over to the bullpen to open the fourth.

“I had a couple chances to make a pitch and get out of both those innings, and I just didn’t do it,” Gibson said.

Gibson yielded seven hits and three walks, with most of the damage against him coming in the third, when he allowed four of his five runs. It was only the second time this year he’s given up that many runs -- he previously allowed six in a loss at Kansas City on May 3 -- and the second time in Baltimore’s past 23 games that its starter allowed more than three earned runs.

It was also Gibson’s shortest start since last Sept. 2, when he gave up seven runs over 1 2/3 innings for the Phillies at San Francisco.

“I thought Gibson had a really good sinker; he just had two really, really long innings,” Hyde said. “Just things weren’t going right.”

They continued to go wrong for the O’s on a wet, soggy night that began with a rain delay of 1 hour and 40 minutes.

The Mariners blew the game open with a seven-run eighth, all of those runs getting charged to left-hander Keegan Akin. In the ninth, the Orioles sent infielder Josh Lester to the mound. He pitched a scoreless frame in only the second mound appearance by a position player for the team this season.

The previous came when McKenna pitched the ninth in a 12-2 loss to Texas on May 26, which had been Baltimore’s largest defeat prior to Friday night.

Although the Orioles (45-29) still have the third-best record in the American League (and fourth in MLB), they’ve lost five of their past eight games. They face some tough competition over the next two weeks, too.

Before the All-Star break, Baltimore still has meetings with the Mariners (now .500 at 37-37), the Yankees (41-35), the Reds (41-35 after 12 straight wins) and the AL Central-leading Twins (39-38).

All the more important that the O’s quickly move past Friday’s loss -- and some of their recent struggles -- and stay focused on finishing the first half strong.

“You’re going to lose 70 to 80 games, depending on how well you play. It’s just one of those games,” Gibson said. “It’s one of those weird ones where a couple big innings kind of did us in, and you’ve got to be able to flush it and not let one loss turn into two.”