BALTIMORE (AP) — On a night in which Boston didn't score a run and plummeted into last place in the AL East, there was reason for optimism in Red Sox Nation.

Rookie Eduardo Rodriguez turned in another sharp performance, one that made a 1-0 loss to the Baltimore Orioles on Tuesday night far easier to swallow.

Rodriguez allowed three hits and three walks over six shutout innings. The former Orioles prospect was vying to become the first left-hander since Kazuhisa Ishii of the Dodgers in 2002 to win his first three major league appearances.

"Through three starts, we're looking at a pretty special young man," Red Sox manager John Farrell said.

Obtained by Boston last July in the trade that sent reliever Andrew Miller to Baltimore, Rodriguez struck out seven and lowered his ERA to 0.44. The 22-year-old has yielded only eight hits and a run over 20 1/3 innings.

"What he does so well is he's able to come back out and establish strike one, even to the first hitter of the inning," Farrell said. "He's done a great job of remaining focused pitch-to-pitch."

After spending four years in the Orioles' minor league system, Rodriguez is now a star with one of Baltimore's division rivals.

"I'm sure there's some guys, if they could pick a scenario, that he would pitch well and we'd win," Orioles manager Buck Showalter said. "I don't wish bad on anybody. I know one thing: The Red Sox will trade with us again. If you always make a pretty even trade, they like working with you."

Steve Pearce scored in the seventh inning on a wild pitch by Matt Barnes, and the Orioles won for the fourth time in five games. Chad Roe (1-0) pitched 1 1/3 innings to earn his first AL victory, and Zach Britton got five outs for his 16th save.

Barnes (2-1) entered in the seventh and immediately gave up the game's first run. Pearce doubled, took third on a single by J.J. Hardy and came home when Barnes bounced a breaking ball past catcher Blake Swihart.

With two on and one out in the eighth, Britton replaced Roe and struck out David Ortiz and Mike Napoli to blunt Boston's final threat.

Red Sox left fielder Hanley Ramirez was removed in the third inning with a bruised left knee. After fouling a ball off his leg, Ramirez remained on the ground for several minutes before resuming his at-bat. He drew a walk and left for a pinch runner.

Orioles starter Miguel Gonzalez departed in the fifth inning with a right groin strain after giving up four hits and a pair of walks.

He was replaced by T.J. McFarland, who got two straight outs to strand a runner on third base.

In the bottom half, Baltimore got two runners on with no outs before Rodriguez retired Manny Machado on a fielder's choice and struck out Delmon Young and Adam Jones. After Jones swung through a third strike, Rodriguez enthusiastically pounded his right fist into his glove four times as he walked off the mound.

"Men on first and second with two outs and then strike him out like that," the lefty said. "It's big for me."

Rodriguez finished with a 1-2-3 sixth inning, getting the final out on a close play at first base in which Nolan Reimold was ruled out after a replay review overturned the initial call.

THIS AND THAT

Red Sox: Rodriguez is the first Red Sox pitcher since 1914 to begin his career with at least seven strikeouts in each of his first three starts. ... Boston has lost seven of its last eight road games. ... It was the fifth time Boston has been shut out since May 8.

Orioles: Showalter has 1,286th career wins, one behind Charlie Grimm for 32nd place on the career list. ... The last time Baltimore beat Boston 1-0 and neither team recorded an RBI was April 9, 1976.

TRAINERS ROOM

Red Sox: RHP Justin Masterson (right shoulder tendinitis) worked out with the Red Sox on the eve of his third rehab appearance, Wednesday for Triple-A Pawtucket.

Orioles: RHP Kevin Gausman (right shoulder tendinitis) will continue his rehab assignment with a start for Double-A Bowie on Thursday.

ON DECK

Red Sox: RHP Rick Porcello starts for Boston on Thursday. He's lost three straight starts and is 3-6 lifetime against Baltimore.

Orioles: LHP Wei-Yin Chen makes his 12th start, looking to double his season win total. He's got a 3.18 ERA, but is 1-4 and winless since May 9.