Chen (4-0) blanked the Yankees until the seventh inning, ultimately allowing a pair of runs on four hits while walking two and striking out four.
The left-hander, among the American League leaders in earned run average, logged his seventh start without a loss to begin the season, tossing 65 of his 105 pitches for strikes.
Pedro Strop hurled a scoreless eighth and Jim Johnson nailed down his 12th save for the Orioles, who remained knotted with Tampa Bay atop the AL East, 2 1/2 games ahead of the Yankees.
Adam Jones went 2-for-3 with a solo homer and J.J. Hardy drove in a pair of runs in the victory.
New York's CC Sabathia (5-1) was tagged with his first loss in eight starts to begin the season. The left-hander surrendered four runs on eight hits over six innings, yielding four walks while fanning six.
Curtis Granderson belted a two-run homer, his 13th home run of the season for New York.
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