OAKLAND, Calif. -- Even when Scott Kazmir is not at peak performance, he still manages to beat Oakland.

Carlos Pena hit a pair of home runs, Kazmir allowed two hits over six innings and the Tampa Bay Rays beat the Athletics 8-2 on Friday night.

Gabe Gross also homered and Jason Bartlett recorded a season-high four hits as the Rays won a series opener on the road for the first time this season.

"I didn't think it was his best evening," A's manager Bob Geren said of Kazmir. "He didn't look as sharp as he has. He threw a lot of pitches for the number of innings but you have to give him credit because he got the job done."

Kazmir (3-1) retired the final 11 batters he faced and did not allow a hit after Jack Cust led off the second with a single. He walked three and struck out two as he improved to 7-2 all-time against the A's, matching his most wins against any team. His 2.48 ERA against them is the best among active starters behind Los Angeles Angels pitcher Ervin Santana.

"I was just throwing to my location," Kazmir said. "I was getting early outs and that was getting me further into the game. After throwing 50 pitches in the first two innings I had to be economical somehow."

Rays manager Joe Maddon liked the way Kazmir rebounded from a rocky start.

"Kaz righted himself and that's still a big part of his game," Maddon said. "He wasn't really on at the start but the last few innings he became more consistent with his strike throwing."

Jack Hannahan homered and Ryan Sweeney singled home a run in the eighth for Oakland, which lost its fifth straight, all to AL East teams. The A's are off to their worst start in eight years.

"There's not a lot of great things to talk about," Geren said. "Any time you're missing the zone and walking guys it's not good. We emphasize throwing strikes and pounding the zone but we just didn't get it done tonight."

A's starter Trevor Cahill (0-2) lasted 2 2/3 innings, giving up seven runs on eight hits with two walks and two strikeouts.

"I didn't have my sinker," Cahill said. "It's a pitch I relied on my first three starts but I know it's not there when I'm giving up a lot of fly balls. It just stays flat."

Carl Crawford doubled home a run in the first and Gross led off the second with his first home run of the season.

The Rays took control with five runs in the third, three on Pena's seventh home run. He took over the AL lead from White Sox outfielder Carlos Quentin with a homer leading off the sixth.

"A win is a win," Pena said. "I just try working hard at keeping things simple."

Dioner Navarro and Akinori Iwamura also drove in runs in the fifth for the Rays.

"We're so explosive at times," Kazmir said. "We put up a seven-spot in the first few innings and that's huge."

Grant Balfour kept the A's off the board with a perfect seventh, but Hannahan led off the eighth against Joe Nelson with his first home run. After Mark Ellis reached second base on a wild pitch following a strikeout and a balk, Sweeney singled him home.

Notes

Rays RHP Jason Isringhausen pitched a scoreless inning for Double-A Montgomery in a 4-2 win over Mobile and will likely made his next appearance at Triple-A Durham. ... A's 1B Jason Giambi sat the game out with a sore hamstring and is expected to play Saturday. ... The Rays have won 5 of their last 7 in Oakland. They are 15-37 overall, still their worst record in any opposing ballpark. ... Hannahan was recalled before the game as the A's sent RHP Sean Gallagher to Triple-A Sacramento. ... Pena recorded his 14th multihomer game. ... The A's have faced six consecutive left-handed starters. ... A's RHP Dan Giese has allowed a home run in each of his three appearances.