BOSTON — The Red Sox scored one of their better victories of the season Thursday at Fenway Park, but it certainly didn't seem that way among the players. There was no joy in the clubhouse as the players packed and headed off to catch a bus to the airport to begin an important nine-game road trip.

Instead of celebrating a come-from-behind 8-5 triumph over Oakland, the room was quiet and serious as the players put on sports jackets and ties.

Virtually all the discussion centered not on David Ortiz' three-run home run that won the game — a blast he called while in the on-deck circle — but instead on the report that the Boston slugger had tested positive for performance-enhancing drugs in 2003.

The Sox overcame deficits of 4-1 and 5-3. They pounded out six extra-base hits. They received good work from their bullpen, capped by a save from Jonathan Papelbon to pick up a rare off day by starting pitcher Jon Lester.

"This is a significant victory," said Mike Lowell in an accurate summation of the day's activities. "We end the home stand on a good note. We've got a big road trip ahead of us. Losing three out of four to finish out the home stand, we would have really felt terrible about that. I think it was an emotional win, something we can carry on into tomorrow."

Other normal circumstances, the Sox would have been having plenty of fun and Ortiz would have been at the center of it. The man known for so long as the team's Mr. Clutch had not hit a really dramatic late-game homer since September of 2007, when he had his last walk-off shot against Tampa Bay.

This one was not quite that dramatic. Boston trailed 5-3 in the seventh and had two runners on when lefty reliever Craig Breslow was brought on to face Ortiz as he already had done a couple times earlier this season. While he waited, Ortiz spoke with Lowell on the on-deck circle.

"He actually called it on the on-deck circle," Lowell said. "I was next to him. He told me he was going to hit a home run."

Lowell's reaction was to make Ortiz a promise.

"I told him, 'If you hit a home run, remember when (Dustin) Pedoira hit the home run off (Rafael) Betancourt in Game Seven (in the 2007 ALCS) and he jumped into you like a teddy bear?' I want you to do that to me."

Ortiz crushed a pitch from Breslow into the seats at the triangle over the Boston bullpen. After he rounded the bases, he kept his bargain -- sort of -- with Lowell. He jumped into Lowell's arms, but Lowell only held on. He did not keep him in the air.

"He probably would have killed me," Lowell said. "I thought that was a great moment."

Doubles by J.D. Drew and Jason Varitek helped Boston score two more runs in the eighth to make it 8-5. Daniel Bard had a perfect eighth and Papelbon allowed one hit in the ninth to save it.

The victory was all the sweeter since it picked up a rare off day by Lester.

Lester had not allowed more than three earned runs in each of his previous 10 starts. Since May 31, he had compiled a 6-2 record with a 1.83 earned-run average, best in the American League and third in the majors behind Tim Lincecum of the Giants and Clayton Kershaw of the Dodgers, who are at 1.73 and 1.39, respectively. Six of the 10 times he allowed zero or one run.

Early on, it was business as usual. Lester retired the first eight batters he faced. He carried a shutout and a 1-0 lead into sixth.

It all fell apart in the sixth. After retiring Adam Kennedy on a grounder to second, Lester walked Orlando Cabrera. Nomar Garciaparra then singled to right. Needing a strikeout, Lester got ahead of Jack Cust 1-and-2, but Cust worked a walk to load the bases.

Rookie Tommy Everidge hit a sacrifice fly to right, tying the score at 1-1. Bobby Crosby then had the big hit, a hard shot to the left of second base. Shortstop Nick Green dove for it, but it got past him. It went for a double that scored the go-ahead run. Rajai Davis followed with a soft single to center that plated two more.

Manager Terry Francona felt it was clear in the walk-to-strikeout ratio that Lester was not sharp. He had been averaging more than strikeout per inning. On this day, he walked three and stuck out only two. Ortiz and the offense covered for him, even if they did not get to celebrate it very much when it was over.