Trevor Cahill's off-speed pitches deserted him when he needed them Monday.
"I didn't feel comfortable out there the whole game," Cahill said after the Diamondbacks' 6-2 loss to the San Diego Padres.
"They were swinging early and I couldn't get my off-speed over for strikes so I had to go with fastballs. With an aggressive team like that, they know what is coming and they are going to hit it."
Cahill allowed four runs — two earned — on seven hits with three walks and three strikeouts. But his mistakes left the ballpark, including Cameron Maybin's monstrous 485-foot home run in the sixth inning — the longest home run ever hit by an opponent at Chase Field and the longest hit in the majors this season.
"I was just trying to throw a slider down in the zone and challenge him," Cahill said. "He was looking for it and he hit it."
The Diamondbacks got a home run of their own — a solo shot by Chris Young in the seventh — and tied a franchise mark with homers in 13 consecutive games.
But Arizona was unable to overcome its own mistakes, including an error on Cahill when he failed to field an underhand toss from Paul Goldschmidt that extended San Diego's three-run sixth inning.
"Bad baseball is bad baseball," said Arizona manager Kirk Gibson. "I never like that. We made it hard on ourselves. We were on a string where we were playing really good defense. Now we have been kicking it around a little bit. Just fundamentally, overall we didn't play good at all."
Alexi Amarista put the Padres with a solo homer in the first.
Maybin homered deep to left-center field and Amarista bounced a two-out double to right-center to spark a three-run sixth.
The Diamondbacks cut the lead to 4-1 on a sacrifice fly by Paul Goldschmidt in the sixth, but Yasmani Grandal homered in the seventh.
Young homered leading off the bottom of the seventh, his eighth home run but only his third since returning from the 15-day disabled list May 18.
Arizona stranded seven runners — four in scoring position.
"We get guys on second and we don't get them over," Gibson said. "We don't get them in. We had opportunities. We had three 3-0 counts and didn't get a good swing at it. We have just not executed well overall. It was a game of poor execution and it's something that we need to fix."
San Diego added a run in the ninth against Brad Ziegler on two walks, a single and a hit batter.
NOTES: The Diamondbacks last homered in 13 straight games in 1999. ... Aaron Hill has hit in 17 straight home games. ... Before the game, the Diamondbacks placed INF John McDonald on the 15-day disabled list with a strained left oblique and recalled from INF Geoff Blum from his rehab assignment with Triple-A Reno. ... RHP Trevor Bauer, who allowed two runs on five hits in over four innings in his major league debut on June 28, will take the mound for the Diamondbacks against RHP Andrew Cashner. Cashner, who had been in the Padres bullpen until June 9, retired 19 of the first 20 Houston batters he faced but got a no-decision against the Astros on June 28.