"When we made mistakes, they had pretty good swings on them," Black said. "They had 15 hits, took some walks. They had a good night."
Jason Kubel hit two home runs, Nos. 28 and 29, and Justin Upton and Aaron Hill each added homers to lead the D-backs (69-71) to victory over the Padres (65-75).
Upton finished with four hits. Teammate Adam Eaton added three hits, his first three-hit game in the Major Leagues.
The Padres were forced to cover the final 6 2/3 innings with relievers after rookie pitcher Casey Kelly (1-1) struggled in his third Major League start, lasting 2 1/3 innings.
"I think Casey wasn't as sharp as his previous two starts," Black said. "His fastball wasn't located and he was up in the zone."
It was the shortest start by a Padres starting pitcher since Ross Ohlendorf also went 2 1/3 innings on Aug. 18 against the Giants.
Kelly allowed two runs in the first inning, one run in the second and three more in the third inning. All told, Kelly allowed six runs on eight hits in 2 1/3 innings, allowing three of the four D-backs home runs.
"I just never really got into a rhythm and I made some bad pitches," Kelly said. "My changeup got some swings and misses, but my fastball command wasn't that good and the same with my curveball."
Across the way, D-backs pitcher Wade Miley, a strong contender for National League Rookie of the Year Award, allowed two runs in the first inning and three more thereafter. Miley (15-9) allowed five runs on eight hits with three walks and six strikeouts.
"I started getting a little frustrated and never really got in a groove," Miley said. "I started overthrowing a little bit and never really found it. Tried to keep us in there, and fortunately we just kept scoring runs."
The Padres answered the D-backs with two runs in the first inning as Jesus Guzman lined a two-out double into the left field corner. But from there, the Padres had trouble matching the kind of firepower Arizona had, as Kubel hit a home run in the first inning and then the third inning.
In fact, Kubel and teammate Aaron Hill went back-to-back with home runs in the third inning to help chase Kelly from the game.
As for Upton, his home run in the fifth inning off Padres reliever Miles Mikolas was to straightaway center field. It was measured at 443 feet, making it the longest home run hit at Petco Park this season.
"It's still a big park," Upton said. "We just got in to a few balls and they carried out for us."
The Padres tried to chip away at Miley, getting a two-run homer from Logan Forsythe to center field in the fourth inning, part of his two-hit night. Forsythe is hitting .342 over his last 23 games and is hitting .365 against left-handed pitching this season.
The loss snapped the Padres' streak of seven consecutive victories over the D-backs.
As for Kelly, who defeated the Braves in his Major League debut on Aug. 29 before getting a no-decision against the Rockies six days ago, he is aware that this is part of the learning curve for a young pitcher.
"I don't think you ever stop learning," said the 22-year-old Kelly. "I'll learn a lot from this and be better down the road because of it."