Cory Luebke's poor decision-making in the field cost him and the San Diego Padres more than his pitching did.

Luebke made two costly mental mistakes that led to two runs as the Padres lost 6-2 to the Los Angeles Dodgers on Monday night in the opener of a three-game series.

Trailing 2-1 in the fifth inning, Luebke fielded a bunt by Dodgers starter Clayton Kershaw that appeared to be rolling into foul territory, then failed to throw out Kershaw at first.

"It was kind of slowing down, so I just tried to get the out," Luebke said. "Hindsight, it was the wrong decision. That's just something I have to be more smart about."

One play later, Luebke threw wide to home on a comebacker, allowing Jamey Carroll to slide around the tag. Kershaw later scored on a sacrifice fly by Casey Blake, who had two hits, to give the Dodgers a 4-1 lead.

"I was frustrated more than anything," Luebke said. "I let some decision-making kind of turn the outcome of the game, and that was more frustrating than anything. The bunt and the throw home and fielding the bunt, I held it a little long and that's on me. That kind of turned the events of the game."

Luebke pitched 7 1-3 innings in his third straight loss, yielding five runs and 10 hits. He struck out two and did not issue a walk.

"He's throwing the ball fine," Padres manager Bud Black said. "Corey's not a secret any more. He's made a number of starts, he's been in the big leagues the entire season, so teams are getting multiple looks at him. He'll continue to make progress, he's going to be fine."

Kershaw pitched a complete game to win his fifth straight start. Kershaw (13-4) tied his career high for wins in a season and moved into a tie with Roy Halladay and Ian Kennedy for the league lead in wins. The All-Star left-hander allowed two runs and six hits, striking out four to add to his league-leading total of 182. He threw 108 pitches, 67 for strikes, walked two and collected his fourth complete game of the season and fifth of his career.

"We've seen him develop before our eyes the last three years," Black said of Kershaw. "He has come into his own. I've seen this year an All-Star pitcher, All-Star caliber no doubt. He leads the league in strikeouts, and you can tell his confidence is growing over his service time."

Matt Kemp doubled, tripled, scored two runs, and drove in his league-leading 83rd run of the season for the Dodgers.

Orlando Hudson's solo homer, his third, in the seventh brought the Padres within 4-2. Cameron Maybin walked to lead off the game and scored San Diego's first run.

Between those innings, Kershaw mostly dominated the Padres, scattering three hits before Hudson drove the first pitch of the inning into the San Diego bullpen beyond the center field fence.

Notes: Dodgers RHP Rubby De La Rosa has a sprained ulnar collateral ligament in his left elbow, MRI results revealed Monday. He will undergo further evaluation from doctors to determine whether surgery is required. ... RHP Erik Hamren pitched a scoreless eighth in his major league debut for the Padres. He was recalled from Double-A San Antonio when San Diego traded reliever Mike Adams to Texas on Sunday.