SAN DIEGO -- Despite San Diego's 6-0 deficit after an inning, Jedd Gyorko was confident the Padres would launch a rally.
"We knew it was obviously a lot of game left," Gyorko said. "It's not the ideal start, but when you have nine innings of baseball, anything can happen."
Gyorko made it happen as much as any player, homering twice and sparking the Padres to an 8-6 come-from-behind victory over the Chicago Cubs on Friday night before an announced crowd of 23,561 at Petco Park.
Gyorko, who went 3-for-4 with four RBIs, hit a three-run homer in the fourth inning and added a solo shot in the eighth. His eight home runs in August set a record for Padres rookies.
"Just getting good pitches and getting good swings," said Gyorko, who has 16 home runs, the most by a Padres rookie since Kevin Kouzmanoff registered 18 in 2007. "Hopefully, I can keep it rolling."
Teammate Will Venable also kept rolling along. Venable, who has hit in 18 of the last 19 games, delivered the go-ahead run with a solo blast off Cubs reliever James Russell with one out in the seventh. The home run, Venable's club-leading 18th, traveled an estimated 441 feet to right and came on the second pitch from Russell (1-5).
"I'm always trying to get ready for a fastball," said Venable, who went 3-for-4 and also had a two-run triple for three RBIs. "I think it was a slider that was just up. Just trying to be aggressive. He threw a good pitch to hit."
Nate Schierholtz homered for the Cubs (54-74), who lost their fourth in a row. San Diego (58-70) won for the fourth time in six games.
The Padres dug themselves out of the 6-0 hole with three runs in the fourth, two in the fifth and a run in the sixth courtesy of an RBI triple by Logan Forsythe.
Nate Vincent (3-1) worked a scoreless inning for the victory. Huston Street gave up a hit in the ninth before posting his 25th save. Vincent and Street combined with relievers Tim Stauffer, Dale Thayer and Luke Gregerson to keep the Cubs scoreless after the first inning.
Stauffer, who relieved an ineffective Edinson Volquez with two outs in the first, allowed just a hit with four strikeouts and a walk in 4 1/3 innings.
"Really, it was Tim Stauffer keeping us in the game and the bullpen doing a great job," Venable said. "You give up a lead like that, the positive thing is that you have a long game still to go to fall back in there. Tim did a great job of giving us that opportunity. We were able to push some (runs) across and eventually take the lead."
Chicago starter Edwin Jackson allowed six runs (five earned) and 10 hits in six-plus innings. Jackson struck out four and walked none on 95 pitches (64 strikes).
"Overall, I did a (crappy) job of holding a lead," Jackson said. "Your team goes out and gives you six runs and any starter that we have, we all feel the same way. If you can't hold a six-run lead, it's real disappointing."
The Cubs greeted Volquez, who had gone 5-0 with a 2.76 ERA in seven career starts against them, by sending 11 batters to the plate in the first inning. The first eight reached base before the Padres caught Brian Bogusevic in a rundown between third and home for the first out.
Dioner Navarro had an RBI single before Schierholtz drilled a 2-2 curveball into the seats in right for a three-run homer and a 4-0 Cubs lead. Bogusevic tripled to right for a 6-0 advantage.
Volquez lasted only 2/3 of an inning. He gave up six runs (five earned) and five hits, walked two and hit a batter.
In the fourth, Gyorko cut the lead in half with a three-run blast off Jackson.
In the fifth, Venable slapped a two-run triple off the right-center fence to pull the Padres to 6-5.
NOTES: Padres OF/1B Kyle Blanks will begin a rehab assignment on Saturday at either Class A Lake Elsinore or Triple-A Tucson. Blanks has been on the disabled list since July 12 with tendinitis in his left Achilles'. ... The Padres are expected decide whether to shut down LF Carlos Quentin before the end of the weekend. He has been on the disabled list since Aug. 10 (retroactive to July 31) with a strained right knee and has shown little improvement. Season-ending surgery is a possibility. ... Cubs RHP Jeff Samardzija (7-11, 4.12 ERA) will face Padres LHP Eric Stults (8-10, 3.70) on Saturday.