SAN DIEGO -- A.J. Pollock's 427-foot grand slam eventually came down in a place not easily reached at Petco Park.

Luckily, Arizona bullpen coach Mark Reed went the extra mile to retrieve the ball for the Diamondbacks' center fielder.

"He looks after me," Pollock said.

Pollock had a career-high five RBIs to lead Arizona over the San Diego Padres 6-3 on Friday night.

Pollock's second-inning grand slam highlighted his outburst.

"Someone will want it," Pollock said. "Someone will think it's cool that it's a grand slam ball."

Rubby De La Rosa (14-8) won for the third time in his last five starts in setting a career high for wins. He allowed three runs (two earned), four hits, with three walks. He struck out two in his 5 2/3 innings of work as Arizona won for the third time in its last five games.

De La Rosa beat the Padres for the fourth time this season.

"Their starter did a great job," interim Padres manager Pat Murphy said.

Casey Kelly (0-1) pitched five innings and was charged with six runs on six hits. It was his first start since Sept. 19, 2012, after a slow recovering from Tommy John surgery in 2013.

Following Pollock's grand slam, Kelly retired the last 11 batters he faced.

"After the first tough couple of innings, I felt like I settled down and started to work the ball down and really started getting some offspeed pitches," Kelly said. "Every outing you are going to have some tough things go on but I try to take the positives out of it and try to keep moving forward."

The Padres chased De La Rosa in the sixth after he walked second baseman Jedd Gyorko and catcher Derek Norris with two outs. Shortstop Alexi Amarista greeted reliever Randall Delgado with a run-scoring single, slicing Arizona's advantage to 6-3.

But Delgado struck out pinch-hitter Brett Wallace to end the threat.

Brad Ziegler pitched the ninth for his 28th save in 30 chances.

Catcher Derek Norris opened the ninth with a single, but the Padres couldn't mount a rally after that.

It was his 26th straight save, the longest active streak in the majors. He is also two shy of J.J. Putz's franchise mark set in 2012.

De La Rosa, who entered 3-0 lifetime against the Padres, allowed two runs (one unearned) over the first five innings.

Pollock set a career-high with the five RBIs and it only took him two at-bats to accomplish the feat. He smashed his first grand slam to straight-away center in the second to pad Arizona's cushion to 6-0.

"He's had a great second half," Diamondbacks manager Chip Hale said. "He's probably been our hottest hitter the last month and a half."

Before Pollock rocked Kelly with a 427-foot shot, De La Rosa reached on a fielder's choice, preceding singles by right fielder Ender Inciarte and second baseman Phil Gosselin.

"You're just trying to find something to get in the outfield and score that one run," he said. "I was just trying to get it elevated in the outfield and get the first run. I was fortunate enough to get them all."

The Padres cut the deficit to 6-1 when right fielder Matt Kemp opened the fourth with a single. He stole second and took third on catcher Wellington Castillo's throwing error. He came home on second baseman Jedd Gyorko's ground out.

First baseman Wil Myers pulled the Padres to within 6-2 with his fifth-inning, RBI single that scored center fielder Travis Jankowski.

Kelly wasn't sharp early and the Diamondbacks made him pay.

Pollock drove in Gosselin with a first-inning single, following Gosselin's one-out double. First baseman Paul Goldschmidt chased in Gosselin with a double for a 2-0 lead.

NOTES: Padres 3B Yangervis Solarte was out of the lineup with a sore right hamstring. Solarte didn't start on Thursday, but may have aggravated his injury in a pinch-hitting role when getting out of the batter's box. ... RHP Bud Norris isn't expected to pitch his weekend with a strained groin. ... Despite an off day on Monday, the Padres are staying with their six-man rotation. ... RHP Josh Johnson has yet to select his date or doctor for his third Tommy John surgery. ... Diamondbacks INF Nick Ahmed remains out with a sore lower back. ... 1B Paul Goldschmidt needs two RBIs to tie Chris Young (408) for fourth-place on the franchise's all-time list. ... RHP Enrique Burgos hasn't pitched since Sept. 11, but manager Chip Hale said he's fit.