BOSTON – Aaron Cook had a rough Red Sox debut. It fit right into how things have been going lately at Fenway Park.

Cook was knocked out in the third inning Saturday and Boston dropped its ninth in 10 games at home, falling to the Baltimore Orioles, 8-2.

Cook, called up to take Josh Beckett’s turn in the rotation, was spiked in the second inning as he covered home plate but stayed in the game.

“It was my decision. I wanted to go out there. I wanted to go and eat some innings,” said Cook. “I know our bullpen has been kind of taxed. I don’t know if it was the best decision, but it was what I wanted to do.”

Baltimore took a 1-0 lead in the second when Chris Davis scored on Jarrod Saltalamacchia’s passed ball. Cook was spiked by Davis’ slide as the pitcher came sliding in knees-first trying to block the plate.

Cook was looked at by a Red Sox trainer on the field, then headed down the dugout steps and Clayton Mortensen came trotting in from the bullpen before Cook came back out. Motensen headed back to the bullpen.

“With the short bullpen, I thought we were going to get lucky,” Red Sox Manager Bobby Valentine said. “I thought about taking him out immediately. I brought in the guy from the bullpen. The medical staff said he’d be fine. I told him, ‘Cookie, it’s on you, man’.”

Cook said he got 11 stitches after he was pulled.

Mark Reynolds hit a three-run homer and Jason Hammel continued his strong start this season for the Orioles. Adam Jones added a two-run homer for Baltimore, which won its fourth straight and 10th in the last 12 games.

Hammel (4-1) limited the Red Sox to a pair of first-inning hits and held them scoreless until he gave up two runs in the seventh.

Adrian Gonzalez had three hits for Boston.

Cook (0-1), signed as a minor league free agent in January, was making his first start after Beckett was skipped due to soreness.

The Orioles, who go for a three-game sweep today, built an 8-0 lead after three.

Hammel retired 16 of 17 batters, allowing only David Ortiz’s fourth-inning walk after the hits in the first before Gonzalez reached on an infield hit and scored on Ryan Sweeney’s double.

Hammel, acquired from Colorado in the offseason, gave up two runs, four hits, struck out eight and walked one over 62/3 innings, raising his ERA to 2.09 from 1.97.

In four of his five previous starts, he was lifted with Baltimore getting three runs or fewer. His last start was a 2-1 loss Monday at the New York Yankees.

The Orioles gave him plenty of run support this time.

With the Orioles leading 1-0, six of the eight batters in the third collected hits and another walked as Baltimore chased Cook with six runs. The two outs came on Robert Andino’s liner to left and Endy Chavez being caught on the front end of a double-steal attempt at third.

Nick Markakis had an RBI single before Jones belted a homer over the Green Monster seats and completely out of Fenway. Wilson Betemit, the last batter Cook faced, had an RBI single after Matt Wieters doubled and Davis singled, making it 5-0.

Mortensen relieved and Reynolds homered into the Monster seats.