TOKYO -- It doesn't matter the city, the country or the continent: A pitcher with dominant stuff can and will hold down a good team.

The defending World Series champion Red Sox were victims of that bit of Baseball 101 in their getaway game against the Oakland Athletics, suffering a 5-1 loss on Wednesday at Tokyo Dome.

Rich Harden, who has always had electric stuff but has struggled to stay healthy, looks primed to have a rebound year, as he mowed through the Sox with relative ease. The hard-throwing righty allowed just three hits and a run, walking three and striking out nine over six innings.

Aside from a towering solo homer by Sox slugger Manny Ramirez, Harden was basically untouched.

"I want to give Rich credit," Ramirez said. "He pitched a great game. He's got a nasty split, his slider was working. He's got it all."

"[Harden] had an overpowering fastball," Red Sox manager Terry Francona added. "When he even got in hitters' counts, he threw his offspeed, his split. He kept us off-balance. That was a very explosive game that he pitched. Again, Manny hit a split out later on, but his stuff was phenomenal, as was his location."

The Sox and A's split the two games of the international Opening Series for Major League Baseball.

"It's a unique experience," Francona said. "I thought our players handled it very well. I was very proud of the way we handled everything that was thrown at us. It's different. I also thought that the Japanese people and the hosts, they were very gracious to us. I thought they embraced the Red Sox and the organization very well. Hopefully we gained some more fans."

Fresh off of opening their regular season, the Sox will now go back to exhibition play as they face the Dodgers three times in Los Angeles, beginning on Friday. The Sox and A's will resume their regular seasons on Tuesday in Oakland with the start of a two-game series.

For Jon Lester, who is hoping to make the leap to sustained excellence this season, this wasn't the type of debut he was hoping for. The Boston lefty was tagged for five hits and four runs over four innings, walking three and striking out four.

"Obviously it wasn't the way I wanted to start the year," Lester said. "I fell behind a lot of hitters early on and [made] one mistake. It was a battle from the beginning. It wasn't just one individual pitch that put me in that situation. I guess I can take some positives out of it. The last inning I threw the ball well and felt like I started to fall into a rhythm a little bit."

The first sign of trouble for Lester occurred in the bottom of the second, when Bobby Crosby lined a one-out double to left. After a walk to Kurt Suzuki, Lester surrendered a two-out RBI single up the middle off the bat of Chris Denorfia.

Lester's problems got a whole lot worse in the third, when Emil Brown bashed a three-run homer to left to give the A's a 4-0 lead.

"Jon had good stuff," Francona said of his starter. "He had a two-seamer on both sides of the plate. He threw all his pitches. He worked himself into some deeper counts and then he tried to throw a backdoor cutter that came right across the middle of the plate. Emil Brown hit the three-run homer, and in a game like this, that's too much because of the way Harden was throwing."

Early on, the Red Sox couldn't get anything going against Harden, who gave up just two hits over the first five innings.

Ramirez delivered a very loud hit in the sixth, ripping career homer No. 491 deep into the seats in left.

"He threw me a good pitch and I saw it pretty good and I hit it out," Ramirez said.

The blast cut the deficit to 4-1.

The A's added insurance off Bryan Corey in the eighth, when Jeff Fiorentino singled home Suzuki.

A pair of former Red Sox relievers help shut the door on Boston in the eighth and ninth. Keith Foulke pitched a scoreless eighth, while Alan Embree allowed a leadoff single to Mike Lowell in the ninth before getting pinch-hitter Sean Casey, in his first at-bat with the Red Sox, to ground into a 4-6-3 double play.

Embree struck out former batterymate Jason Varitek to end the game and hand Boston its first loss of the season.

For Ramirez, the two games in Japan showed that he may be ready to have the monster season many are expecting. He had two doubles, a homer and drove in five of Boston's seven runs in the two contests. Now he hopes to continue that as the Red Sox return to the States.

"We'll have a good flight and go from there," Ramirez said. "This is my third time here. I love it. Like I said, I've been here three times, and every time I've come here, it's been the same. I love Japan."