Chen fixed his first inning woes this season, posting a 1.69 ERA over 16 starts. He allowed only one home run.
The Red Sox weren't interested in trends tonight, just taking an early lead.
Shane Victorino drew a one-out walk off Chen in the bottom of the first, moved to third base on Dustin Pedroia's double off the Green Monster in left field and scored on David Ortiz's sacrifice fly to center.
Pedroia is now 5-for-11 lifetime against Chen.
Chen has allowed only four runs in the first inning this season. He's also surrendered four in the second, third, fourth and fifth innings.
It's the later innings that jump up and bite him. Chen's permitted 17 runs after the fifth this season.
Before tonight, Chen was holding opponents to a .200 average with runners on base, third-lowest among American League starters. Boston's Clay Buchholz leads at .139.
Red Sox left-hander Felix Doubront has retired the first six Orioles, striking out three.
In Chen's last 23 starts, the Orioles have scored only 58 runs while he's been in the game, and 47 more after he's come out. In his last 40 starts, the Orioles have scored three runs or fewer 26 times while he's been on the mound.
They owe him.
Down on the farm, Triple-A Norfolk's Steve Johnson allowed two runs and five hits in 4 1/3 innings against Gwinnett, with three walks, five strikeouts and a home run. He threw 92 pitches, 53 for strikes.
Braves second baseman Dan Uggla, on an injury-rehab assignment, homered for Gwinnett.
Jonathan Schoop hit his ninth home run for the Tides.
Machado has three sac flies in the last two games.
Doubront filled the bases by allowing singles to J.J. Hardy and Danny Valencia, and hitting Steve Pearce.
Hardy was 0-for-11 lifetime against Doubront. Valencia is now 3-for-5 with a double and home run.
Update II: Victorino hit his 100th career home run in the bottom of the third, a two-run shot that gave Boston a 3-2 lead. And Mike Napoli homered to left leading off the bottom of the fourth, his 17th this season.
Chen has allowed 12 home runs this season, including six in his last three starts.
This is only the third time in 17 starts that Chen has permitted more than three earned runs.