De La Rosa pitched seven innings, giving up two runs, one earned, on just five hits and striking out six. The D-backs right-hander has allowed just one earned run over his last 15 innings and has won consecutive starts for the first time since his first two outings of the season.
"He did a great job, had great stuff tonight," D-backs manager Chip Hale said of De La Rosa. "I think when you face him you have to be aggressive. That's the truth, for me, because he's got such good stuff."
Shields gave up four runs in six innings of work. The right-hander has just one win in his last five starts and has given up four earned runs in two of his last three outings.
"It was one of those games where I had to grind it out," Shields said.
MOMENTS THAT MATTERED Early offense: Shields is typically great in the first three innings but the D-backs tagged him early. A.J. Pollock led off the first with a double and later scored on a Paul Goldschmidt groundout. In the third, Aaron Hill and Welington Castillo hit back-to-back two-out RBI doubles, followed by an RBI single from Nick Ahmed that gave the D-backs a 4-0 lead. Shields had given up just 12 runs in the first three innings in his first 14 starts.
"That was probably the biggest part of the game for us," Hale said. "We battled him. I thought we did a great job of battling and getting the ball up and making him throw strikes."
De La Rosa wiggles away: The Padres loaded the bases against De La Rosa in the fourth and picked up their first run when Justin Upton walked to force in Shields from third. But Matt Kemp struck out on four pitches to end the threat. More >
Going deep: De La Rosa retired the Padres in order in the seventh, his third 1-2-3 inning of the game, and faced two batters in the eighth before exiting. The D-backs right-hander has pitched at least seven innings in six of his 14 starts. He also improved to 3-0 with a 1.04 ERA in four career starts against the Padres.
Missed opportunity: Thanks to a pair of D-backs errors to start the eighth, the Padres had a runner at third with no outs and then the bases loaded with one out but managed just one run, on a sacrifice fly from Cory Spangenberg that brought in Upton. The Padres were 0-for-6 with runners in scoring position.
Pat Murphy won his first challenge as Padres interim manager in the third inning. Goldschmidt tried to score from third on a pitch that got behind Padres catcher Derek Norris, but Norris corralled the ricochet and beat Goldschmidt to the plate. Home plate umpire James Hoye called Goldschmidt safe before the call was overturned after a 1-minute, 10-second replay review.
Murphy also was successful in challenging a stolen base attempt by Arizona's A.J. Pollock in the sixth. It took 27 seconds to overturn the safe call by second base umpire Bill Welke.
WHAT'S NEXT Padres: Right-hander Tyson Ross takes the mound for the Padres in the second game of the series, at 7:10 p.m. MST Saturday. Ross gave up two runs to the D-backs in five innings and took a no-decision May 9 in Arizona. He's won only one start since May 15.
D-backs: The D-backs counter with Robbie Ray, who has been great since joining the rotation when Archie Bradley was injured, posting an 0.96 ERA in his last three starts which included seven scoreless innings against the Angels his last time out.