SAN DIEGO -- The Colorado Rockies know how to make the most of their trips to spacious Petco Park.
The Rockies, who were swept in their previous series against NL West-leading Arizona, won for the 12th time in 15 games at San Diego. Colorado is 6-2 at Petco this season.
"It's not a hitter's ballpark, but ultimately, it's not that bad," Colorado catcher Chris Iannetta said. "Home runs to right field, even to center field, for righties are nonexistent. But the hits are there. You just have to make sure you get good swings."
"I think we did some very, very good things offensively," manager Jim Tracy said.
Fowler, who tripled in the series opener on Friday night, had a pair of doubles and has six extra-base hits in his last four games. The speedy center fielder has 26 extra-base hits in 47 games since being recalled from Triple-A Colorado Springs on July 15.
"He once again battled and when they nicked him to get the game to 5-4, I liked the way he stayed tall," Tracy said. "He's a young 23-year-old kid and I promise you between now and the end of the year, you're going to see his best command game. When you do, it's going to be a dynamic performance."
"They've been doing a really good job," Iannetta said. "They had a little bit of adversity throughout the course of year when the starters were not going deep into games. That puts a lot of pressure on your bullpen. But this is what we expect out of them."
Colorado scored three runs in the fourth inning to grab the lead for good. Tulowitzki led off with a double to right against Cory Luebke (5-8) and scored on Helton's single to center. Ryan Spilborghs added an RBI double and Iannetta hit a sacrifice fly to give the Rockies a 4-2 lead.
Fowler started the Colorado fifth with a single and scored on Tulowitzki's base hit.
"I've got to get the leadoff man out," Luebke said. "Both those innings, their guys led off with doubles. That makes it a little harder."
Guzman hit a two-run double in the bottom half of the fifth to get San Diego within one, but the Padres were unable to complete the comeback.
San Diego is mired in its longest losing streak since a 10-game slide last summer that started its collapse after leading the NL West for much of the season.
Luebke (5-8) gave up five runs and eight hits in 4 1/3 innings.
"I just wasn't consistent," Luebke said. "I couldn't locate my fastball. That's always been a key to my success, getting ahead. I didn't really give us a chance."
Venable led off the first with his sixth homer. It was his fourth career leadoff homer, all this season. Venable also doubled and scored on Guzman's double in the fifth.
San Diego is 18-34 against the NL West and .500 against both the East and Central. ... Padres OF Cameron Maybin (sore right wrist) was out of the starting lineup for the seventh straight game. ... RHP Aaron Cook (3-8, 5.82 ERA) will start for Colorado on Sunday. He is 14-5 against the Padres in his career. Padres RHP Mat Latos (6-13, 3.82) will bid for his second victory in 12 starts.