The Orioles had drawn into a 6-6 tie with a three-run rally in the seventh against Duke Welker, including Michael Almanzar's two-run homer.
Torrid Russell Martin had helped the Pirates build a 6-3 lead with his fourth homer of the spring, a two-run blow in the second.
Martin connected after Michael Martinez had delivered a two-out single off Baltimore starter Chris Tillman, putting the Bucs up, 4-1.
Since starting the spring 0-for-3, Martin has eight hits in 12 at-bats.
"You always feel pretty good in the spring, but I never had these results," said Martin, who was 6-for-40 last spring, his first with the Pirates, and drove in a total of three runs. He has nine RBIs in six Grapefruit League games. "I just feel a lot more comfortable."
Pittsburgh jumped into a 2-0 lead in the first on Chris Dickerson's run-scoring single and an RBI force-play grounder by Travis Ishikawa. Steve Clevenger halved that deficit with a solo homer in the second off Ray Jackson.
In the fourth, Clevenger singled in front of a two-run homer by Steve Pearce off Vin Mazzaro that made it 4-3. Clint Barmes greeted lefty reliever T.J. McFarland with an RBI single in the fourth for a 5-3 Pirates lead.
Chase d'Arnaud made it 6-3 with a two-out homer in the sixth on an 0-and-2 delivery from righty Brock Huntzinger.
Tillman worked into the fourth inning, allowing five runs on six hits, while striking out four without a walk.
"I'm going based off feel now," Tillman said. "And as long as I feel like I executed the pitch well, physically felt well, that's all that really matters… [my] first-pitch strikes could have been better and two-strike approach."
Up next for Pirates: The Bucs on Tuesday have their first of two off-days (the other will be on March 18), then will travel to Ft. Myers to meet the Twins on Wednesday. Gerrit Cole is scheduled to start that 1:05 p.m. ET game, and could be Pittsburgh's first pitcher to pick up a bat this spring, as the club tentatively plans to begin having its starting pitchers hit in preparation for regular-season play.