ARLINGTON – A chance for a big inning presented itself to the Rangers in the fifth Monday night, but the American League's worst offense this month came up empty.

A chance for a big inning presented itself to the Los Angeles Angels in the sixth, and the AL's best offense this season didn't miss out.

The Angels scored four runs against Vicente Padilla in the sixth en route to a 5-2 victory in the opener of an important three-game series at Rangers Ballpark in Arlington. The win moved the Angels 2 ½ games ahead of the Rangers in the AL West.

Padilla might make for an easy target after his worst outing since earlier this month at Yankee Stadium, when he twice hit Mark Teixeira with a pitch. But offense continues to be the Rangers' downfall.

"They had one big inning, and that was the ballgame right there," manager Ron Washington said. "It very easily could have been the other way."

The Rangers were leading, 2-1, in the fifth, and Ian Kinsler and Michael Young started the inning with a single and a walk. Runners were at first and second with no outs, and David Murphy and Marlon Byrd – who had staked the Rangers to their lead with back-to-back homers in the third – were coming up.

Murphy saw one pitch from Sean O'Sullivan (2-0), a fastball he liked but popped up for the first out. Byrd saw two pitches, grounding the second one to third base for an inning-ending double play.

Byrd, who went 3-for-4 and was the only player in the lineup with more than one hit, put the blame on his shoulders.

"If I drive those runs in, don't ground into the double play, do something better with the change-up, maybe it gives Padilla a bigger cushion," Byrd said. "Right there, I've got to get those runs in."

Murphy, who said he swung early on the pitch, was frustrated by his at-bat but also by the offense's extended slump.

"I'm getting to the point where it's a struggle to think about what might have been," he said. "I'm tired of dwelling on the past and what we're not doing.

"We've struggled enough to where we need to take a positive attitude into tomorrow. If you want to think about this one in the clubhouse, the ride home, we can't start letting bad games roll into tomorrow."

The Angels seized on their opportunity. Vladimir Guerrero led off the sixth with a single through the infield shift, and Juan Rivera drove what looked to be a decent pitch from Padilla (6-4) over the center-field fence.

Kendry Morales followed with a home run almost in the same spot, and back-to-back singles by Maicer Izturis and Mike Napoli ended Padilla's night.

Padilla, who last week outdueled National League ERA leader Dan Haren, said he didn't have his best fastball, especially in the sixth.

"If I don't have it, sometimes I have problems," Padilla said. "In the first four innings, I was still making pitches. In the last couple of innings, it was different."

The difference, though, continues to be an offense that has been stymied by Kevin Correia, Chad Gaudin and O'Sullivan during a three-game losing streak.

That played out over six outs in the fifth and sixth innings.

"We had two guys on. We had the part of our lineup we wanted coming up," Murphy said of the Rangers' fifth. "The inning ended pretty quickly. There's not much more to say."