BALTIMORE -- Baltimore sandwiched between Boston and New York sounded like the recipe for a delectable early-season entrée for the surging Rays. Unfortunately for the defending American League champions, the flavor of the series hasn't been particularly savory.

After opening the season by taking two-out-of-three against the Red Sox in Fenway Park, the Rays traveled to Baltimore for a three-game series with the Orioles before heading back to St. Petersburg for the home opener against the Yankees. But no teams in the American League East are pushovers, and the Orioles are living proof as they beat the Rays in the opener Friday night before delivering a first-inning knockout punch on Saturday night en route to a 6-0 win over the Rays in front of a crowd of 15,108 at Camden Yards.

Jeff Niemann made his first start of the season after being named the No. 5 starter in the Rays rotation on Sunday and he got off to a less-than-auspicious beginning.

Brian Roberts doubled to lead off for the Orioles in the first. Niemann then hit Adam Jones before Nick Markakis doubled home Roberts for Baltimore's first run. After Aubrey Huff walked to load the bases, Melvin Mora unloaded them with a grand slam to left-center field to put Baltimore up 5-0.

"The biggest thing going through your mind at that point is you have to manage the game," Rays manager Joe Maddon said. "That's when you really manage the game, because of course it's going to be hard to come back. Although with our offense, you think you can. Big point is your bullpen, how do you keep your pitching staff intact?"

Niemann finished out the first then settled in to pitch an additional 4 1/3 scoreless innings before getting lifted after walking consecutive hitters with one out in the sixth. Brian Shouse took over for Niemann and gave up a single to Roberts to load the bases. Jones then hit into a fielder's choice to drive home the Orioles' sixth run.

"[Niemann] pitched very well [after the first]," Maddon said. "And the big thing was for him to do that because obviously if he didn't do that it would have blown up our bullpen for several days.

"It was a big start for him and he was amped up a bit. But I was very impressed. He easily could have thrown in the towel there and messed us up for several days. But he didn't. And that was the impressive part of what he did today."

Niemann wasn't happy about his performance, but he took solace in the fact he did not give in after the rough start.

"There's an ugly side to this and a good side, you know," Niemann said. "You just have to address the issues the next few days and come out there and get after it the next time."

At the other end of the spectrum, Orioles starter Jeremy Guthrie handcuffed the Rays for six innings, allowing no runs on five hits while striking out two to pick up his second win of the season.

"He was good," said Evan Longoria, who went 2-for-4 but was unable to hit a home run after doing so in the previous four games. "Really couldn't get a read on him, especially early because the way he throws his fastball, sometimes it cuts, and sometimes it sinks. So you can't really know and size a guy up when he's doing that. He made it tough on us. And sometimes you tip your cap."

The Rays were 0-for-11 with runners in scoring position on Saturday night and they left nine runners on base.

"Their lineup is very good," Orioles manager Dave Trembley said. "He had to bare down and make some big pitches to get out of some innings. He didn't flinch and was helped by some good fielding plays."

After Guthrie's departure, the Orioles got a stellar relief effort from Matt Albers, Jamie Walker, and Chris Ray, who combined to keep the Rays scoreless for the final three innings of the game.

The Rays' offense has been a little bit stymied in the early going of the season, relying heavily on home runs to account for most of their scoring.

"We haven't really strung together a group of hits," Longoria said. "I think once we get that going we'll be all right. We have been lately just kind of quick strike; base hit, home run; base hit, base hit, home run."

Maddon sounded nowhere near panicked about the offense's situation, but he does recognize a need for improvement.

"We've got to start scoring runs other than just with home runs," Maddon said. "It's going to happen. Just right now we're not doing it."