For a change, it was the offense that rescued the hard-throwing De La Rosa.
Colorado's stagnant offense belted out a season-high 16 hits and scored its most runs of the year as the team moved percentage points ahead of San Francisco for first place in the NL West.
"We all know we can be the best offensive team in the league. It's just that we need to show it," Carlos Gonzalez said. "We've just got to continue to do the same thing."
Their outburst at the plate helped offset quite a night by Maybin, who finished 4 for 4 with two homers and three RBIs. It was the first multihomer game of his career and second straight contest in which he's had four hits.
"It's the approach," Maybin explained. "I was just hitting a lot of balls to the left side of the field, so the approach was to back it up, trust my hands and trust my ability, just try to start using the whole field a little bit more.
"I think when I'm doing that I feel like I got a chance to do some good things."
De La Rosa (5-1) was erratic but effective enough to earn his first win this month. The lefty lasted 5 2/3 innings, giving up five runs and a season-high nine hits. He struck out three and walked three.
"I was not so good today," said De La Rosa, who had a single and an RBI on a fielder's choice. "But when you get that kind of run support, you pitch more relaxed."
The heart of the Rockies' order -- Gonzalez, Tulowitzki and Todd Helton -- did a good portion of the damage as the trio combined for six hits, six runs and five RBIs. Gonzalez had a triple and two stolen bases, while Helton added a double.
Helton left soon after scoring a run in the sixth due to tightness in his left calf. He was going to be reevaluated Saturday.
"I don't think it's serious," Rockies manager Jim Tracy said. "I don't think he pulled the calf, but he strained it a little bit, there's no question or he would not have come out of the game. Todd Helton doesn't come out unless there's something going on."
Tulowitzki had his first multihit game since April 26. He finished 3 for 5, including his 10th homer of the season.
"Great to see Tulo have the offensive game that he had," Tracy said.
Fresh off a 23-hit performance Wednesday in Milwaukee, the Padres had 11 against the Rockies. Maybin hit a solo homer in the second and a two-run shot in the seventh that drew the Padres to 9-7.
Maybin is the first Padres player to have two straight four-hit games since Reggie Sanders in July 1999 at Coors Field.
"He's a very talented athlete," Padres manager Bud Black said. "We think where he is in his career at  years old, he has the makings of a tremendous all-around player."
Dustin Moseley (1-5) had a rough first appearance at Coors Field, surrendering six runs and nine hits in just four innings, his shortest outing of the season.
The righty entered the contest with the top road ERA in the majors, too, a mark that soared from 0.68 to 2.35.
Moseley never settled into a groove after giving up three runs in a 40-pitch first inning. He was lifted for a pinch hitter in the fourth inning.
"I didn't know if I was going to get any outs. I just wasn't sharp," Moseley said. "There's really no other explanation, no excuse that I have. It's just I wasn't sharp, and it's what happens when you face big league hitters and you're not sharp."
Before the game, Wigginton was activated off the disabled list after being bothered by a strained oblique since late April.
Wigginton went 1 for 5 with a double.
To make room on the roster, the Rockies sent struggling infielder Ian Stewart to Triple-A Colorado Springs to work on his swing. Stewart was hitting .064 in 21 games with Colorado this season.
"This was hard for me, seeing the average up there on the scoreboard every day and feeling pressure to get a hit every time I was up," Stewart said. "I'm just going to try to go down there and have fun. See what happens."
Padres 2B Orlando Hudson (strained right hamstring) will begin a rehab assignment at Triple-A Tucson. ... OF Dexter Fowler (bruised left knee) didn't start for a second straight game. He came off the bench in the eighth and delivered an insurance run with a bloop single to left that scored Gonzalez. ... The Rockies halted a two-game slide.