"My fastball was down and I didn't use my changeup much, but when I did, I thought it was effective," said Maine, who has allowed only one earned run in his last 20 2-3 innings and lowered his ERA from 2.33 to 1.78.
Mets manager Willie Randolph has the right-hander, who struck out seven and walked one, slotted to pitch the first game of a three-game series at Atlanta on April 4.
"He looked really good," Randolph said. "Pitchers are starting to lock in now and get ready for our campaign."
The Orioles also got an encouraging outing from struggling Adam Loewen, who carried a 12.27 ERA into the game and didn't survive the second inning in his last start March 19. The left-hander, who missed much of last season with a stress fracture in his left elbow, allowed a run and two hits in five innings.
"This kind of wipes my slate clean," said Loewen, who struck out three and walked three. "I pretty much forgot everything up to this point. Now it's on to my next start and I think when I make my next start this will all be forgotten. I can just get my six innings in and I'll get ready for the season."
Luis Castillo singled in Brady Clark in the third inning and finished with two hits for the Mets.
Joe Smith followed Maine with 1 2-3 scoreless innings and Nelson Figueroa recorded the final four outs for New York.
