Perez's blast to left field was a two-run jack and Moustakas followed shot to right-center. Both came off left-handed reliever Sean Doolittle after the A's had taken a 1-0 lead in the bottom of the fifth.
Ventura struck out six and gave up just two hits in 4 1/3 innings.
"I felt good, I felt like my pitches were working for me. I just hope I can continue to do that," Ventura said.
"He kept the ball down, used both sides of the plate with his changeup late in the count and that worked," Perez said of Ventura, who has a 2.89 ERA and nine strikeouts in 9 1/3 innings this spring.
Scott Kazmir, making his second Cactus League start, gave up a hit and a walk, while striking out three in four innings for the A's.
"To be able to go in there with no outs and a couple runners on, and get out of that was big," said Kazmir, who has not given up a run in seven innings. "I wasn't particularly sharp, but a lot of my secondary pitches got me out of some jams."
Up next: A.J. Griffin will look for a bounce-back outing as he makes his third Cactus League start on Thursday night at 7:05 p.m. PT against the Colorado Rockies at Phoenix Municipal Stadium. Griffin gave up three runs and six hits in his last start, also against the Rockies, and has a 9.00 ERA this spring. The game, which will be televised on MLB Network and MLB.TV, will offer the A's their first chance to test the new replay system.
Chris Gabel is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.