BALTIMORE - Just when it seemed as if Baltimore had figured out a way to keep Jon Lester from being dominant, the Boston ace found his old form against his divisional rival.
The Orioles had difficulty solving Lester once again while Jason Hammel's struggles continued in Sunday's 5-0 loss to the Red Sox in front of 32,891 at Camden Yards.
Baltimore lost for the fifth time in six games and dropped a series to Boston for the first time since July, 2011. Lester had a lot to do with Sunday's loss - the Red Sox lefty struck out eight in seven innings and kept the Orioles (58-48) from mounting any offense.
Meanwhile, Hammel dropped to 7-8 (5.20 ERA) and hasn't won since May 27. He struggled with his command, falling behind batters early and often, and threw 97 pitches in 5 1-3 innings.
The result was another loss, and the 10th straight winless start for Hammel.
"I'm definitely aware of it," said Hammel, who gave up three runs and six hits along with a season-high five walks. "Baseball's not fun right now for me. It's frustrating for me. I'm making good pitches at times and they're getting hit, and the bad ones they're letting go."
Lester was 14-0 in 20 career starts against Baltimore before losing two in a row, most recently June 16 when he allowed five runs on nine hits in five innings in a 5-0 loss. He was anything but off Sunday. Lester (10-6) improved to 8-1 all-time at Camden Yards and got plenty of help, particularly from David Ortiz.
The Boston slugger went 4 for 4 with a home run and two RBIs, one day after being ejected after a strikeout and destroying a dugout phone with his bat. Ortiz now has 11 seasons with 20 or more homers for Boston, which ties him with Dwight Evans and Jim Rice for second most in team history. Ted Williams is the Sox leader with 16.
Lester carried a 3-0 lead into the sixth - by way of Ortiz's two-run shot to left-center in the third inning - when the Orioles had their best chance to get back into the game.
Chris Davis reached base on an error and Adam Jones followed with a single to put runners on first and second with no outs, but Lester struck out Matt Wieters and got J.J. Hardy to ground into a 5-4-3 double play to end the inning.
"You know what you're going to get with him," said right fielder Nick Markakis, who singled twice and walked against Lester. "You know it's going to be a battle."
Lester retired 11 in a row in the early innings and left the Orioles hitless with runners in scoring position (0 for 6).
Boston (63-43) collected 10 hits against Baltimore pitchers and padded its lead in the eighth thanks to a two-run single from Jarrod Saltalamacchia.
Mike Napoli's RBI single in the first put Boston on top early - the Red Sox improved to 44-9 when they score first - and set the tone for another frustrating start by Hammel, who needed 27 pitches to escape the frame.
Orioles manager Buck Showalter said "there wasn't much margin for error for him today because of Lester. He's pretty good."
Hammel has been his own harshest critic during these struggles, but said it's a matter of finding his way as the season progresses.
"If you constantly stomp on yourself saying you're terrible, pretty soon you start believing that," he said. "I'm not doing that. It's obviously very frustrating. I am not doing what I know I can do. But it could be a lot worse.
"Keep grinding, it is what it is. We've still got a lot of baseball left. It's a long season. I honestly still think the best baseball for me is going to be ahead."