Ryan Flaherty hit a grand slam and Chris Tillman tossed eight dominant innings, as the Baltimore Orioles took down the Boston Red Sox, 9-1, in the opener of a three-game series.
Tillman (9-2) gave up just one unearned run on one hit while striking out four and walking two for the Orioles, who remained one game behind the Yankees for first place in the AL East. New York beat Toronto on Friday.
Flaherty also had an RBI double for Baltimore, which holds the top wild card spot in the AL. Chris Davis added a two-run homer.
"It feels good, and I am glad I could help my team win," Flaherty said. "Whatever that is, defense, offense and tonight it was with the bat. So it was good."
Dustin Pedroia knocked in the lone run for the Red Sox, who have lost three in a row and seven of eight.
Boston starter Aaron Cook (4-11) lasted just one-plus innings, allowing six runs on five hits while walking three. Alfredo Aceves gave up three runs on six hits over 3 2/3 innings of relief.
Boston's only hit and lone run came in the first inning. Scott Podsednik reached base on a bunt single, moved to second on second baseman Flaherty's throwing error, advanced to third on Pedro Ciriaco's sacrifice bunt and scored on Pedroia's sacrifice fly.
But the Orioles exploded for six runs in the bottom half. Nate McLouth led off with a single and scored on Davis' one-out blast to right. Jim Thome singled, Mark Reynolds walked and Manny Machado singled to load the bases with two outs. Flaherty followed with his first career grand slam, making it a 6-1 contest.
Cook was replaced by Aceves after walking the first two batters in the second. Davis grounded into a double play and Adam Jones grounded out to end the inning.
Baltimore tacked on three more runs in the fifth to make it a 9-1 game. With two outs, Reynolds, Machado and Flaherty hit three straight doubles to knock in a pair of runs. Taylor Teagarden followed with an RBI single.
Tillman retired the final 14 batters he faced, while Troy Patton pitched a scoreless ninth to complete the one-hitter.
"We were behind his fastball most of the time," Red Sox manager Bobby Valentine said of Tillman. "We were out in front of his breaking ball. His curveball, he threw effectively. We didn't solve him."
The Orioles are 11-5 against the Red Sox this season ... Flaherty's grand slam was Baltimore's 122nd homer at Camden Yards this season, surpassing the 1996 club for most home runs at home in a single season ... Orioles catcher Matt Wieters missed Friday's game after his wife gave birth to the couple's first child earlier in the day ... Cook fell to 0-3 in four career starts versus the Orioles.