Kirk Gibson is getting tired of losing to the San Diego Padres.

"They've beaten us seven times in a row. Let's go," Arizona's manager said Friday night after Chase Headley drove in four runs on two home runs, including a solo shot leading off the eighth inning that lifted the Padres to a 6-5 victory over the Diamondbacks.

Coming off a hot August in which he had 10 homers and 31 RBIs to win NL Player of the Month honors, Headley extended his career highs to 26 home runs and 98 RBIs.

The Diamondbacks weren't able to cool him off.

After the Diamondbacks rallied from a 5-0 deficit to tie the game in the eighth, Headley opened the bottom of the inning with a shot to straightaway center field off David Hernandez (2-3).

In the third, Headley hit a monster three-run homer that almost landed in the giant paint can in left field at Petco Park.

The defending NL West champion Diamondbacks entered the night 6 ½ games behind St. Louis for the second NL wild card. Arizona has been outscored 48-25 in their seven straight losses to San Diego.

The Padres have won three straight and 13 of 17.

Brad Brach (2-4) got the final out of the eighth for the win. Luke Gregerson pitched the ninth for his fifth save in nine chances.

In the third, Headley drove a 2-2 pitch from rookie Tyler Skaggs off the side of the 10-foot paint can that sits between the Western Metal Supply Co. building and the stands in left field to give the Padres a 5-0 lead. If a player homers into the can, Frazee Paint will donate $500,000 to the Padres Foundation.

"Headley's on fire," Gibson said. "We know that. You just have to make good pitches. If you don't make good pitches, he's going to pound you like he did tonight."

Yasmani Grandal hit a two-run double for the Padres in the first inning.

The Diamondbacks began their comeback when Tyler Wheeler's long fly ball to right field in the fifth went for a two-run double when Chris Denorfia missed making the catch against the wall. That brought in Miguel Montero and Chris Johnson, who opened the inning with singles off Andrew Cashner.

Wheeler added an RBI double in seventh to bring in Montero with an unearned run. Montero struck out leading off the inning but reached after the ball got away from catcher Grandal.

Arizona tied it in the eighth when Montero hit a two-run double off Tommy Layne, the third of four Padres relievers that inning.

Cashner returned to the rotation after spending nearly two months on the disabled list with a strained right lat. He allowed two runs and four hits in five innings, struck out five and walked none.

Skaggs, making his fourth big league start, went only three innings, allowing five runs and five hits. He struck out five and walked one.

"It seems like things happen every time we play them," Skaggs said. "It was one of those outings where you have to forget about it. I thought I threw the ball well except for a couple of pitches."

Notes: Arizona's Tyler Graham made his big league debut as a pinch-runner in the ninth. ... Cashner was making his fourth start of the season and first-ever start at Petco Park. ... The series continues Saturday night when LHP Wade Miley (14-9, 2.90 ERA) is scheduled to start opposite San Diego's Casey Kelly (1-0, 3.86), who is scheduled to make his third big league start.