Chase Headley is in a zone right now for the San Diego Padres and looks to keep his recent surge going tonight in the second portion of a three-game series versus the Arizona Diamondbacks.

Headley homered twice and drove in four runs last night in a 6-5 win over the Diamondbacks at Petco Park. Headley, who has already set career highs in home runs, RBI and walks this season, entered the night batting .313 with five doubles, 16 home runs, 52 RBI and 36 runs scored since the All-Star break.

"The last couple of months, he's been in a great spot confidence-wise and swing-wise," Padres manager Bud Black said. "There's no doubt he's swinging the bat great from both sides."

Headley's leadoff homer in the eighth was the difference. He owns a .338 average, 14 homers, 26 runs and 46 RBI since Aug. 1.

Yasmani Grandal drove in two runs, while Headley, Chris Denorfia and Logan Forsythe each had two hits and a pair of runs scored for San Diego, which has won three in a row and 13 of its last 17 games. The Padres are 9 1/2 games off a wild card spot and opened a nine-game homestand on Friday.

Yonder Alonso was 0-for-4 and is still tied with Benito Santiago (1987) for the club's single-season rookie-record for doubles with 33.

Andrew Cashner allowed two runs in five innings for the no-decision and Brad Brach picked up the win by getting the final out of the eighth inning. Luke Gregerson tallied his fifth save with a scoreless ninth.

Padres youngster Casey Kelly draws the third start of the season and of his career tonight, and is 1-0 with a 3.86 earned run average in the first two. Kelly threw six shutout innings in a win versus Atlanta on Aug. 27, then did not factor in the outcome of an 11-10 loss at Colorado on Sunday. He was banged around for seven runs -- five earned -- and eight hits in 5 2/3 frames.

Kelly, a right-hander, has never faced the Diamondbacks.

Arizona is fading from the playoff picture and last night's loss put the club 6 1/2 games off a wild card spot.

Tyler Skaggs started for the Diamondbacks and lasted just three innings, allowing five hits and five runs. David Hernandez served up Headley's solo home run in the bottom of the ninth to absorb the loss.

"I felt like I had good stuff today...felt like I threw the ball well," Skaggs said. "Just a couple mistake pitches...a couple balls that were blooped in and just wasn't my best today."

Miguel Montero hit a game-tying, two-run double in the eighth inning, while Ryan Wheeler had two hits and three RBI in defeat, Arizona's 10th in 14 tries. Montero has hit in 13 straight road games and 19 of the last 23.

The D-backs are 4-4 on a 10-game road trip and 2-4 as the guest since winning six in a row away from home.

Wade Miley gets the nod for Arizona this evening and he is 14-9 with a 2.90 earned run average in 27 games (24 starts). Miley is 0-1 in his last two outings and did not factor in the outcome of a 5-4 loss at Los Angeles on Sunday, as he gave up three runs and nine hits in 6 2/3 frames.

Miley, an All-Star back in July, is 0-2 with a 5.40 ERA in three career starts against the Padres and lost to them back on June 1.

The Padres have won nine of the 13 matchups so far with the Diamondbacks and recently swept them in a three-game series from Aug. 24-26. San Diego has won seven in a row against Arizona.