BALTIMORE -- James Shields proved the old adage true again: It's not about whether you get knocked down. The important thing is whether you get back up.

Shields took a punch to the gut in the first inning, then he delivered the punches for the next six innings to lead a 6-2 Rays' win over the Orioles on Monday in front of an Opening Day crowd of 46,807 at Camden Yards.

Shields, who signed a long-term deal in January that could last as long as seven years and, with incentives, could be worth as much as $44 million, walked the first batter he faced on Monday. The uncharacteristic free pass to Brian Roberts sent up a warning flare that Shields might struggle. One out later, Nick Markakis singled and Kevin Millar followed with a deep fly ball that ricocheted off Carl Crawford's glove in left for a double to give the Orioles a 2-0 lead. And just like that, "same old Rays" seemed to echo around the chilly ballpark.

Shields is one of the reasons why the Rays believe they are not those same old Rays. He proved why in the final six innings of his outing by allowing just three additional hits to pick up his first win of the season. A combined bullpen effort of Trever Miller, Al Reyes and Dan Wheeler pitched the final two innings.

Shields "wasn't as sharp as he can be with his command overall, but nevertheless, competes all the time," Rays manager Joe Maddon said. "... He's a young professional that knows how to compete and that's what he did today."

The Rays starter confessed to being "a little bit pumped up" in the early going.

"But today was one of those days where I couldn't get a rhythm at all," Shields said. "I think the last inning was the inning I got into my rhythm. I just had to find a way to keep us in the ballgame.

"When you're getting behind every hitter, it's kind of hard to pitch like that. It's hard to get in a rhythm when you're not getting ahead in the count. I battled and we rolled some double plays today and we got out of some innings."

Akinori Iwamura, who moved from third base to second this spring, served as the pivotman for the first double play in the fourth, while new shortstop Jason Bartlett made the relay to first to complete the double play in the sixth.

Dioner Navarro got the Rays' offense started in the third when he singled to lead off the inning before O's starter Jeremy Guthrie hit Bartlett. Iwamura then hit into a fielder's choice to advance Navarro to third, where he scored on Crawford's swinging bunt that Melvin Mora booted at third. B.J. Upton singled home two more to put the Rays up 3-2.

The Rays never looked back.

Eric Hinske found out he made the team on Saturday and later that day found out he would be starting in right field Opening Day. The move turned out to be the right one when he deposited a Guthrie fastball into the right-field stands for the Rays' first home run of the season and a 4-2 lead.

"It's one of those where you hit it and you hardly feel it," Hinske said. "Put a good swing on a fastball right out over the plate."

The Rays scored twice in the sixth on RBI singles by Navarro and Bartlett to reach the final margin.

Maddon smiled after the game when talking about his team's state of mind before the Monday's opener.

"We were charged up," Maddon said. "The guys were really charged up. ... They were all charged up before the game. I think we were just a little bit over amped."

How amped were the Rays Monday? Maddon went to a football vernacular to equate his team's level of excitement to players who play on special teams.

Shields seemed to like his manager's assessment and smiled.

"Opening Day is Opening Day," Shields said. "No matter what anybody says, it's the first day of the season and we're all going to be pumped up."