Peralta has been doing better this year against left-handed pitchers, but Dodgers manager Don Mattingly did not hesitate to yank right-handed starter Mike Bolsinger to bring in lefty J.P. Howell to face Peralta.
"I trust David against the lefties now," D-backs manager Chip Hale said. "When they bring in the [lefty] reliever he's going to see some of them."
Peralta hit a fly ball to left to end the inning.
The first hitter of the top of the fifth for the Dodgers, Corey Seager hit a fly ball foul down the left field line that a racing Peralta appeared to be able to make a play on by the left-field seats.
However a fan reached over and stuck his glove above Peralta's and made the catch.
Granted a reprieve at the plate, Seager hit the very next pitch over the wall in right for his first big league home run.
"I was hustling all the way trying to make the play and I was under the ball and the fan just put his glove over mine," Peralta said. "In the moment I got [mad], because you saw what happened on the next pitch, he hit a home run."
After he had some time to calm down, Peralta regretted getting so upset.
"You know they're fans that get excited when the ball comes to them," Peralta said. "They're coming to the game to have fun and enjoy the game. Every fan, when they see the ball coming towards them, they're going to get excited and try to get the ball."
Hale said in retrospect he wished he would have challenged the call.
"That was probably my mistake," Hale said. "That's a challengeable play. We heard [the fan] was in the field of play and it was questionable whether David was going to get there. It looked like David was going to get under the ball, but he wasn't camping under it. I don't know if we would have gotten it overturned, but I probably should have taken a shot."
When Peralta came up in the seventh the Dodgers once again brought in a lefty -- Luis Avilan -- to face him and this time he homered to right.
"It's going to happen," Peralta said of not coming through in the fourth. "You fail. You just have to learn from that. You see I failed with the lefty with bases loaded and then hit a homer off the lefty, but it's part of the game. There's nothing we can do. Just learn."