"Five of their seven runs came on home runs and walks today," manager Kirk Gibson said. "In this ballpark, that's not what you want to do. Got to keep the ball out of the air."
Anderson gave up a pair of runs in the first after allowing back-to-back singles to start the game, but both runners scored on what proved to be productive outs.
After the rocky first inning, it looked like Anderson had settled down as he pitched three scoreless frames.
But in the fifth, his command failed him.
Anderson (7-6) walked Padres starting pitcher Ian Kennedy to start the inning after going ahead in the count, 0-2. He then threw four straight balls to Yangervis Solarte. He almost escaped the self-inflicted jam, getting a double play from Rymer Liriano, but another walk led to what ended up being the decisive blow.
After Seth Smith walked, Yasmani Grandal crushed a 1-0 fastball into the right-field stands, giving the Padres a 5-0 lead.
"I kind of just lost feel in that fifth inning," Anderson said. "I can't really tell you why. I felt good going into the game, my command was coming back to my fastball in the third and fourth innings, so no real rhyme or reason. Just got to work on it."
Said Grandal: "He was a little wild and not throwing strikes. When a guy is like that, you're looking for a fastball to hit."
Anderson left the game after the inning, tying his career high with four walks and ultimately being saddled with his sixth loss.
While Anderson struggled, Kennedy (10-11) cruised early in the game, not running into trouble until the fifth inning, when the D-backs started to mount a comeback.
After loading the bases, the D-backs got on the board with a two-run single by Miguel Montero. Ender Inciarte cut the deficit to two with an RBI double in the next inning.
But the D-backs could not keep the Padres within reach.
With reliever Matt Stites on the mound in the eighth inning, pinch-hitter Will Venable extended the Padres' lead back to four runs with a two-run homer, effectively ending any momentum the D-backs had.
"They got huge hits," Gibson said. "Five runs came on the home run. That's two hits. That's what you hope to do."
Cliff Pennington got a run back for the D-backs with a home run in the bottom of the eighth, but the team went down in order in the ninth.
"We had opportunities," Gibson said. "We left 10 guys out there today. They got more of their guys in than we did."