Last year's Opening Day starter, Arrieta extended his scoreless inning streak to 14 2/3 innings in the process, allowing six hits and two walks in an impressive outing. The 27-year-old, who also pitched in an exhibition game against Spain, has appeared in five spring games (four starts), allowing three earned runs on 13 hits and eight walks with 16 strikeouts over 17 1/3 innings.
Sanchez, who can opt out of his contract on Sunday, cruised through his outing, with third baseman Manny Machado owning both of the Orioles' hits against him with a pair of singles. Sanchez issued a walk to Lew Ford in the second inning for Baltimore's only other baserunner through five innings.
Starling Marte reached twice for the Pirates, with a leadoff double in the first and a fifth-inning walk, while Travis Snider doubled in the sixth off Ford's foot on a ball that he lost in the lights.
Pittsburgh's Gaby Sanchez was scratched before the game with an allergic reaction, with Brad Hawpe replacing him as the designated hitter.
Orioles reliever Luis Ayala pitched a scoreless seventh.
Up next for the Orioles: Right-hander Steve Johnson will get the start for the Orioles in Port Charlotte at 1:05 p.m. ET on Friday, with Rays righty Jeff Niemann opposing him. Jair Jurrjens is also scheduled to go multiple innings for Baltimore.
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.