Adley Rutschman went deep for the second straight game, and the Baltimore Orioles posted four of their runs on homers in a 5-1 victory over the visiting Oakland Athletics on Monday night.

Ryan Mountcastle drilled a two-run homer in the first inning and Austin Hays added a solo shot in the sixth as the Orioles had a strong start to the four-game series.

Orioles starter Kyle Gibson (3-0) gave up one run and five hits in 6 1/3 innings. Two of his three walks came in the first inning, and he struck out four.

The Athletics lost their fifth game in a row, but unlike back-to-back 11-0 losses during the weekend at Tampa Bay, they were competitive in this one. Oakland finished with eight hits, including two by Jace Peterson.

It was the fifth time in 10 games that Oakland failed to score more than one run.

Athletics starter JP Sears (0-1) worked five innings in his second outing of the season. He allowed three runs, though two of the three hits he surrendered were home runs. He struck out four and walked one.

Five Oakland pitchers combined on a six-hitter.

This is the fourth series of the season for the Orioles, and they've won the opener each time.

Baltimore center fielder Cedric Mullins and manager Brandon Hyde were ejected in the seventh inning arguing a strike call.

Oakland scored first on Ramon Laureano's two-out triple in the first inning. Mountcastle put the Orioles on top in the bottom of the inning with his third homer of the season.

Rutschman went deep for the third time this season in the third. Hays' second homer of the year came three innings later.

Hays doubled with two outs in the eighth and scored on a single by Ramon Urias for some added insurance.

Bryan Baker, Cionel Perez and Felix Bautista worked in relief for Baltimore, with Baker and Perez picking up two strikeouts and Bautista fanning three.

--Field Level Media