Daisuke Matsuzaka's latest bid for his 50th career win was done in when he failed to retire a single batter in the second inning.

Now he might have to wait a few weeks longer with a possible disabled list stint for a stiff neck on the horizon.

Matsuzaka allowed home runs to former teammates Josh Reddick and Brandon Moss and the Boston Red Sox lost to the Oakland Athletics 6-1 on Monday night.

Matsuzaka (0-3) has been dealing with a stiff neck that prevented him from throwing a bullpen session between starts and he struggled right from the start against the A's, allowing five runs in one-plus inning.

"Dice obviously didn't have his good stuff tonight," manager Bobby Valentine said. "He went out with a big crick in his neck. We were hoping he was going to work through it. As it turns out he didn't work through it."

Jarrod Parker (5-3) was the beneficiary of the early offense, allowing one run and six hits in 6 2-3 innings.

Parker allowed one run or fewer for the seventh time in his past eight starts and 10th time in 14 career starts. He is the first pitcher since Ferdie Schupp of the New York Giants to do that in his first 14 starts, although Schupp was a spot starter who pitched mostly in relief when he did it from 1913-17.

"It seems like it's the same game every time," A's manager Bob Melvin said. "They get one run. Today started off a little spotty for him, a double in the corner and they score a run early. It looked like maybe he didn't have his best stuff. He then certainly did his thing."

Parker allowed a double to Daniel Nava to start the game, followed by an RBI single by Dustin Pedroia.

But the Red Sox didn't threaten again until putting the first two runners on in the seventh. Parker got Mike Aviles to hit into a forceout and struck out Nick Punto. Sean Doolittle came in and struck out Nava to end the threat, marking the seventh time in Parker's last eight starts he has held the opposition to one run or less.

"Parker was able to throw his off-speed stuff when he was behind in the count," Valentine said. "He used both sides of the plate with his fastball. A couple of times when we had a threat going, he snuffed it out pretty quickly."

Matsuzaka was chased before retiring a batter in the second inning and failed for the sixth time to join Hideo Nomo and Tomo Ohka as the only Japanese pitchers with 50 career wins. Matsuzaka has not won a game since May 8, 2011, against Minnesota.

"My body wasn't in the condition it probably should have been but despite the home run in the first inning, I got out of that inning and I thought I'd be able to fight through a few more innings," Matsuzaka said through a translator.

Reddick, acquired last December in a trade for injured closer Andrew Bailey and outfielder Ryan Sweeney, hit his 19th homer with two outs in the first inning to tie the game at 1.

"It's always going to be something special to do well against these guys," Reddick said.

Matsuzaka matched the shortest start of his career.

Seth Smith opened the four-run second with a drive to center field that hit off Ryan Kalish's glove for a double. Derek Norris then walked and Moss hit the next pitch over the right-field fence for his ninth homer in 22 games with Oakland. Moss played 49 games with Boston in 2007-08 but has come into his own with the A's in the past month.

Matsuzaka was replaced by Clayton Mortensen after Brandon Inge singled and Cliff Pennington walked. Reddick added a sacrifice fly that made it 5-1.

Mortensen helped save the Boston bullpen by pitching five innings, allowing only a sacrifice fly to Inge in the sixth inning.

"It's always nice to be able to pick the team up and soak up some innings so our bullpen can stay fresh for this series," Mortensen said.

NOTES: Boston 3B Will Middlebrooks will be out for at least a few days with an injured left hamstring. Valentine said the team would likely bring up another position player on Tuesday and either place Middlebrooks on the DL or send down one of the 13 pitchers. ... RHP Bartolo Colon (6-7) is expected to come off a DL stint for a strained right oblique to make his first start since June 17 on Tuesday against Jon Lester (5-5).