The Diamondbacks gave up 14 hits, walked 10 batters and made a series of defensive miscues.
"For me as manager and our coaching staff, it was embarrassing. That is the easiest way to put it," manager Chip Hale said. "We made some gaffes on defense that we worked so hard in spring training and we are close enough to spring training where we shouldn't make those mistakes."
Arizona has lost three of its first four games, all at home.
"Maybe there is too much stress, too much anxiety on them," Hale said. "Their minds aren't free enough to work. It was a tough game to watch for everybody."
The Diamondbacks were up 3-0, 4-2 and 6-4 on Thursday, but starter Rubby De La Rosa (0-1) couldn't hold the leads. The right-hander lasted just 3 1/3 innings, allowing seven runs and six hits.
In the first four games of the season, Arizona starters have some shaky numbers.
The Diamondbacks pitchers held a postgame meeting Thursday.
"It's frustrating. I think the guys are a little frustrated at this point," Hale said. "I think the pitchers are frustrated. I think the whole organization is frustrated."
Information from The Associated Press was used in this report.