Nothing routine about it

The routine has become rote. Jonathan Papelbon comes out of the bullpen, stares down hitters with his menacing glare, gets three outs (sometimes more), and the Red Sox go home winners.

But Oakland A's rookie right fielder Travis Buck interrupted the sanctity of that ritual last night.

Buck, who entered the game batting .190, belted an 0-and-2 pitch from Papelbon into the right-field grandstand with Bobby Crosby aboard to erase a 4-2 Boston lead. The home run, Buck's third of the season, allowed Oakland to score in the top of the 10th to take a 5-4 victory last night at Fenway Park.

Before Buck bucked the trend, Boston was the only team in the majors without a blown save (9 for 9). His timely long ball capped a career-high three-hit performance for the 23-year-old , who at this time last year was playing for the Single-A Stockton Ports of the California League.

Buck, who played at Arizona State with Red Sox second baseman Dustin Pedroia and was 36th overall in 2005, had never faced Papelbon, before but word of his deadly splitter proceeded him.

Buck got a fastball on 0-2 and made the most of it, although he wasn't sure that was enough.

"Fortunately enough he missed a spot," said Buck, who went 3 for 5 with a double and two runs scored. "When I hit it, I saw [right fielder Eric] Hinske scaling the wall and I was like, 'No way, that's all I got.' Fortunately, it was enough and it got out."

Buck's homer gave the offensively challenged A's, who hit .230 in April (their lowest average in a full month since June 1982) a big lift. Oakland came to the East Coast as losers of four of five and seemed to be headed for another loss before Buck's blast.

"We're not lighting the world on fire offensively, but we've had some pretty good games where we've have some clutch hits and timely hitting and we have to do that," said designated hitter Mike Piazza. "We're just not scoring a lot of runs. That was a big hit and a big lift for us."

A's manager Bob Geren was not there to see Buck's big hit. He was ejected in the fifth for arguing an Eric Chavez check-swing strikeout.

"It was much more painful watching the game on TV," he said. "You felt more nerves. It was a different experience, very weird. It's happened before in Triple A, but you don't have a TV in the clubhouse. I've sat in the clubhouse with binoculars at times."

Triple A is about where Buck figured to be this season after advancing as high as Double A last season. But when he had a strong spring and center fielder Mark Kotsay was felled by back woes Buck was on the Opening Day roster.

Injuries have decimated the Oakland outfield. The A's put Bobby Kielty on the disabled list with a strained left calf prior to last night's game and Nick Swisher is battling a strained hamstring. Things got so desperate that general manager Billy Beane had to pull off a deal for Atlanta outfielder Ryan Langerhans on Sunday, even though Langerhans was batting .069 at the time.

Buck wasn't doing much better, as he was 1 for his last 18 entering last night, although 10 of his last 15 hits have been better than a single. "This time last year I was in high-A and now here I am in the big leagues on a team that wants me to be productive every time I'm in there," said Buck. "They have the feeling and the confidence in me that I can do it. Coming through in a really big game against an unbelievable team is a boost for me confidence-wise and hopefully it will get us going."

Buck might have come through in the clutch like a veteran, but he still has the carefree naiveté of a neophyte. He marveled at the noise and enthusiasm of the Fenway Park crowd, calling the atmosphere "pretty cool." That wide-eyed innocence probably helped him against Papelbon. Buck honestly didn't know any better than to think he could hit the Sox sublime closer.

Piazza said he remembered what is was like his first time around.

"You're so amped up the whole season. You're in the big leagues and the adrenaline is kicking and you're facing great pitching," said Piazza. "You have to have a let-it-all-hang-out and nothing-to-lose mentality because no one is expecting him to be here, and if he just relaxes and realizes there is no pressure on him, hopefully he'll just keep doing that."

An exuberant Buck did strike out once when it counted, he couldn't recall his last game-tying or game-winning homer.

"I can't really remember," he said. "Tonight. I haven't hit too many, but I'll definitely remember this one."

Christopher L. Gasper can be reached at cgasper@globe.com.