The Yankees' pitching held its own in the scoreless duel until the sixth, when a one-out double by Pirates middle infielder Pedro Ciriaco drove in the game's first run.
The inning began with a leadoff single from Chris Snyder. Pinch-runner Jeremy Farrell replaced Snyder, who finished 2-for-2, and came around to score when Ciriaco's extra-base hit bounced high off the left-field wall.
The run -- and loss -- were charged to Yankees right-hander Brian Anderson, who also hit a batter in his one inning of work.
Pittsburgh padded its lead off New York's Eric Wordekemper in the seventh. Josh Fields' sacrifice fly scored Garrett Jones, who led off the inning with a walk and advanced to third on Steve Pearce's double.
The afternoon began with scoreless two-inning starts from New York's Phil Hughes and Pittsburgh's James McDonald. Hughes erased a leadoff walk with a double play and then retired the final four hitters he faced.
McDonald scattered two hits in an otherwise efficient appearance. Five of the six outs he recorded came on ground balls.
"I felt good," McDonald said afterward. "The goal today was to get ahead, throw strikes and really be efficient. Today was a success."
Despite pitching well, Hughes would like to build on his performance.
"I don't want to go out there and lay an egg every time I take the mound in Spring Training just because I feel like I have a spot locked up," Hughes said. "I still want to go out and compete and work on things."
Both Aaron Thompson and Daniel McCutchen matched McDonald with scoreless two-inning appearances. McCutchen's outing was especially encouraging after he had been knocked around for three runs on two hits and a pair of walks in a one-inning outing over the weekend. He did not allow a hit on Tuesday.
For the Yankees, David Robertson and Steve Garrison each made scoreless appearances after Hughes' exit. Robertson struck out two in one inning of work, while Garrison allowed just two singles in a two-inning outing.
Eric Chavez had the only multihit game for New York, which tallied just four hits. Curtis Granderson had the team's only extra-base hit -- a two-out triple in the first inning.
Up next for the Pirates: Ross Ohlendorf will make his spring debut at McKechnie Field in a 1:05 p.m. ET game against the Twins on Wednesday. Ohlendorf is the only Pirates starter who hasn't yet pitched in Grapefruit League play. Closer Joel Hanrahan is scheduled to make his second appearance, as is Tony Watson, who is trying to make the bullpen as a left-hander. The Twins will start lefty Brian Duensing in the contest. Former Pirates closer Matt Capps is also scheduled to pitch.
Up next for the Yankees: After enduring a difficult 2010 campaign that saw his confidence and focus waver at times, right-hander A.J. Burnett begins his spring push to get back on track as the Yankees entertain the Astros in a 1:05 p.m. start at George M. Steinbrenner Field on Wednesday. Derek Jeter is set to be in New York's lineup as he continues to acclimate to a new no-stride approach at the plate; Jeter is 1-for-6 thus far in Grapefruit League play. Right-hander Bud Norris will get the ball for Houston.
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.