Turley, a distant third cousin of former Yanks hurler and 1958 World Series MVP Bob Turley, tossed two wild pitches and committed a throwing error in the ugly frame, which also featured a two-run throwing error by Yankees shortstop Jayson Nix.
"I think you saw some nerves in a young pitcher early on," Yankees manager Joe Girardi said. "It's a good experience to go through because, as you move up, you're going to be asked to do more and more, and I think you can take something from this."
Gardner paced the Yanks' offense for the afternoon, clubbing a bases-clearing triple to deep center field in the second inning off Baltimore starter Jake Arrieta.
Chris Stewart also had a run-scoring single off Arrieta, who was charged with three runs on two hits in 1 2/3 innings. Arrieta walked two and struck out none in a 38-pitch outing.
Orioles left fielder Steve Pearce drove in three runs. Pearce, who briefly played for the Yanks last season, belted an RBI double off Turley in the first inning and added a two-run single facing Cody Eppley in the second inning.
Dylan Bundy, ranked by MLB.com as the Orioles' top prospect, tossed two scoreless innings, allowing one hit while striking out one and walking one.
The Yankees, who made five errors in the contest, batted around and scored three times in the ninth inning, highlighted by Kyle Roller's two-run single, before leaving the bases loaded.
"It was pretty sloppy," Girardi said. "We've got a lot of young kids playing. Are you going to see that sometimes? Probably. We don't really have a whole lot of our regulars healthy right now. Some of them aren't playing, so you're going to see some of it."
Up next for the Yankees: The Yankees will play two split-squad games on Thursday, sending one roster to visit the Astros for a 1:05 p.m. ET start in Kissimmee, Fla., live on MLB.TV Right-hander Brett Marshall will start for New York in that contest, opposed by Houston right-hander Lucas Harrell. In the home contest against the Blue Jays, also at 1:05 and on MLB.TV, right-hander David Phelps will face off against right-hander Brandon Morrow. The game at George M. Steinbrenner Field will be televised on YES and can be heard on WCBS 880 AM.