PHOENIX -- Offseason trades cost San Diego Padres outfielder Will Venable a starting job, but when opportunity knocked Friday, he was right there to answer.

Making only his fifth start of the season, Venable had three hits including a home and drove in the go-ahead run in the Padres' 6-5 victory over the Arizona Diamondbacks at Chase Field.

"We have three outfielders out there who should be out there," said Venable of newcomers Justin Upton, Matt Kemp and Wil Myers. "Some good players. And I understand the situation. Don't get discouraged. You have to be patient, and when the opportunity does come you can't press too much. It's just about going out there and letting it happen.

Venable, pressed into service when Myers moved to first base after Yonder Alonso was placed on the disabled list, singled to break a tie at 5 in the seventh inning after Upton walked and stole second base against right-hander Enrique Burgos (0-1).

"He's such a great Padre," manager Bud Black said of Venable. "His starts and his at-bats have been a little limited this year because of our outfield situation. But that was a great game for Will. That was a huge hit, obviously."

Venable homered in the second inning and tripled and scored in the fourth, finishing a double short of the first cycle in San Diego (16-15) history. He struck out in his final at-bat after entering the game in an 0-for-16 slump.

"You can't try and hit a double," Venable said. "I've tried to hit homers before, but I don't know how you try to hit and double. It's not something you are pursuing."

Myers, who had a career-high four hits in his first major league start at first base, was a triple short of the cycle. He singled in his final at-bat in the eighth inning and was thrown out attempting to stretch it into a double.

Second baseman Cory Spangenberg tripled, scored twice and walked four times for the Padres (16-15), who had lost three of four.

Arizona shortstop Chris Owings, center fielder A.J. Pollock, first baseman Paul Goldschmidt and right fielder David Peralta homered off Padres right-hander James Shields (4-0), who gave up five runs in six innings and was credited with the victory when San Diego scored in the top of the seventh.

Pollock, Goldschmidt and Peralta hit solo shots within four batters in the fifth and sixth innings, Peralta's homer tying the game at five before the Padres went ahead on Venable's single.

"It was a pretty bad day for me," Shields said. "I was getting behind in the count for the most part and they were capitalizing on it. But the good news is, we won the game. The guys did a great job of fighting back."

Shields has given up seven homers and 10 runs in his last two starts but has won both games.

"The ball has been flying. That's about it," Shields said.

Arizona starter Jeremy Hellickson gave up five runs and two homers in 4 2-3 innings. His ERA is 5.85, third-highest among National League starters.

"I feel like any time we score five runs, I have to come out with the win," Hellickson said. "It's just frustrating. Everybody else did their part."

Arizona (13-15) has scored 34 runs in the last four games, two in Colorado. Their three-game winning streak was broken Friday.

"In this ballpark and in Colorado both, you have to score runs," Arizona manager Chip Hale said. "The ball jumps out of here. You have to be able to score runs, so we can score more than that.

NOTES: San Diego 1B Yonder Alonso (scapula) was placed on the 15-day disabled list Friday, a day after aggravating a shoulder injury when he landed awkwardly while fielding a ground ball. "It could be two, three, four weeks," Alonso said. He was tied for seventh in the National League with a .333 batting average and has four doubles, a triple and a homer. CF Wil Myers started at first on Friday. Myers had played four innings at first in his first two major league seasons with Tampa Bay. ... OF Abraham Almonte was to be recalled from Triple-A El Paso to take Alonso's roster spot, although he was not expected to arrive until Saturday, San Diego manager Bud Black said. ... RHP Shawn Kelley (calf) was activated from the disabled list Friday and RHP Nick Vincent was optioned to El Paso to create a roster spot. ... Entering the game, Arizona led the major leagues in batting average (.333), on-base percentage (.371) and slugging percentage (.500) since April 27. ... Arizona RHP Jeremy Hellickson and San Diego RHP James Shields, Friday's starting pitchers, were teammates in Tampa Bay from 2010 to 2012. Shields had 44 victories during that span and Hellickson had 35.