Orioles left-hander Wei-Yin Chen hadn't allowed a run in his last 13 innings before tonight.
He fell behind 1-0 in the first after a line drive fell in front of center fielder Adam Jones to spark the Mariners' two-out rally.
He fell behind 3-0 in the second after Jesus Montero tripled on a ball that bounced off the heel of Jones' glove as he raced to the warning track.
It could have been a whole lot worse in the first. Chen threw 28 pitches, the last a called third strike on Dustin Ackley to leave the bases loaded. He only surrendered one run.
It could have been a whole lot better. Chen retired the first two batters before Kendrys Morales sent a line drive to center. Jones charged the ball and reached down, but he couldn't hold onto it. If he makes the catch, Chen is back in the dugout.
Chen compounded his problems by walking Michael Morse, and Jason Bay followed with an RBI double. Justin Smoak walked before Ackley struck out.
Jones crashed face-first into the padded fence while chasing Montero's ball and stayed down on the warning track. He slowly rose to his feet and still looked like he was trying to clear the cob webs as play resumed.
For whatever reason, Jones is having trouble keeping the ball in his glove. It lands there but it doesn't stay there.
Michael Saunders singled with one out to score Montero, and he came home with two outs on Morales' single - a scorching liner that second baseman Ryan Flaherty could only wave at from his backhand side. Flaherty was close enough to have a shot at it, but it didn't happen.
Chen is up to 51 pitches after two innings.
The Orioles are trying to win their fifth consecutive series, which they haven't done since 1999.
It's more likely to happen if they score some runs for Chen and tighten up the defense behind him.
Update: Chen can't blame the defense for Morse's two-run homer in the fourth.
Mariners 5, Orioles 0.
The Orioles could have traded for Morse over the winter, but they passed on him. It would have been interesting to pit him against Chris Davis in a strong man competition.
UMBC product Zach Clark may be approaching his major league debut. Chen is up to 93 pitches in four innings. Manager Buck Showalter will want to replace him with a right-hander instead of left-hander T.J. McFarland.
Update II: Chen is charged with five runs and eight hits in four innings, tying the shortest outing of his career. He walked three, struck out six, served up a home run and threw a wild pitch. He threw 93 pitches, 59 for strikes.
Chen didn't catch many breaks, because balls behind him weren't being caught, but his stuff was lacking tonight. He grew more frustrated by the inning. He didn't hide it.
Clark pitched a scoreless fifth in his first big league appearance. He issued his first walk and struck out his first batter.
It's all downhill from here.