Brandon Maurer thought the first-inning woes that hampered the first two starts of his career were in the past. The last three outings had been an impressive turnaround for the Seattle rookie in his first month in the majors.

Trouble with the first inning returned on Tuesday night.

Nate McLouth led off the game with his second homer of the season, Baltimore battered Maurer for four runs in the first inning and the Orioles beat the Mariners 7-2.

McLouth blew a bubble with his gum as he rounded the bases. Over his last 10 games, the Orioles' leadoff man is hitting .485 and has scored 14 runs.

"I needed to settle and take deep breaths and throw better strikes," Maurer said. "You've got to notice they are (aggressive) and not throw a fastball first pitch or if you do, throw it outside, something that is not easy to hit."

The first two starts of Maurer's career were highlighted by struggles in the first inning. In his first home start against Houston, Maurer gave up six runs and seven hits and recorded just two outs.

But Maurer (2-4) had been outstanding over his previous three starts with a 2-1 record and a 1.89 ERA over 19 innings. It seemed to be proof that Seattle made the right decision going with the young right-hander out of spring training.

His performance against Baltimore was certainly a step back.

"He just wasn't executing pitches there in the first inning and with them being that aggressive up there, ready to hit, things happened quick," Seattle manager Eric Wedge said.

Baltimore didn't stop after McLouth's homer. Manny Machado followed with a double and scored after a pair of wild pitches by Maurer, both of which were sliders in the dirt that bounced away from catcher Kelly Shoppach and went to the backstop. Nick Markakis singled and Chris Davis walked before Matt Wieters capped Baltimore's big first inning with a two-run double.

The Orioles tacked on two more in the sixth on Chris Dickerson's first RBIs of the season and another in the seventh.

"I said coming in here we wanted to get him a game and get some at-bats under his belt. Chris has a lot of skills that we want to take advantage of and it's nice to get some production there," Baltimore manager Buck Showalter said.