Friedrich struck out five in five innings, with the only run being Grandal's first homer, a solo shot in the fourth. It came on the heels of Jeff Francis' six scoreless innings in Friday night's 10-2 victory over the Padres. Friedrich had entered with an 11.64 ERA in four starts.
"I've been saying all along, 'Yeah, the ball flies sometimes, but you still have to make good pitches,'" Friedrich said. "For them to elevate it and have it go that far -- maybe it goes another five feet, but it's still not a good pitch if it goes that far. I finally just made some good pitches."
But Friedrich's tones were quiet because another pitcher's issues at home continued.
Jeremy Guthrie (3-7) yielded three runs -- Grandal's two-run shot from the left side (his off Friedrich was from the right side) that gave the Padres a 3-2 lead, and the first of Alexi Amarista's two homers for a 4-2 lead in the seventh. Guthrie, who was acquired from the Orioles during the offseason and was the Rockies' Opening Day starter, fell to 1-4 with a 9.96 ERA at home.
Amarista launched a three-run shot off Adam Ottavino in a four-run eighth that proved important.
Grandal is the first player in Major League history to hit homers from opposite sides of the plate for his first two career hits in the same game.
"I can't describe how remarkable it is," said Grandal, fresh from Triple-A Tuscon, after the Padres sent down slumping catcher Nick Hundley. "Just getting the callup was something I had been looking to. To hit two home runs in my first two hits is incredible."
Grandal upstaged Rockies rookie catcher Wilin Rosario, who homered off winning pitcher Edinson Volquez (5-7) to open the bottom of the fifth and improve his total to 13, tops among NL rookies. Rosario also homered Friday night.
"I'd never seen that guy," Rosario said of Grandal. "The only thing I can tell you is he's strong, like me."
Friedrich pointed out that in a sense he'd never seen Grandal. The only video the Rockies had of him was from the left side.
"I said let's just see how it goes," Friedrich said. "The first at-bat went all right. Then I left a pitch up and he punched it like he should. He looks good behind the plate, too."
After Rosario's homer, Eric Young drew a walk and scored from first when Grandal threw wildly to first on Dexter Fowler's bunt. Padres right fielder Chris Denorfia nailed Fowler at third with a perfect throw, but the Rockies had a 2-1 lead.
Volquez, usually the victim of low run support, bobbed and weaved through six innings and held the Rockies to three hits and two runs, one earned. He struck out eight, but also walked six.
The Rockies' lead and Friedrich's strong work wound up wasted.
"We pitched badly from the sixth inning on, because the job that Christian Friedrich did was just exceptional," Rockies manager Jim Tracy said.
Guthrie has given up a team-high 17 home runs.
"One was a strike one slider, one was a changeup eight inches off the plate," Guthrie said. "Both were in poor locations because they were hit for homers."
Ottavino, whose big league action before this year was spot duty with the Cardinals in 2010, has generally pitched well since being called up from Triple-A Colorado Springs. But the combination of inexperience between him and Rosario left Tracy perplexed in the eighth.
Tracy was particularly bothered by an RBI double by Cameron Maybin, who is hitting .204, just before the second Amarista homer.
The two-strike pitch to Maybin, after he had missed a slider by at least three feet that I know of, we turned around and threw him a fastball," Tracy said. "I did not understand that at all."
Tracy said Rosario has been improving at calling pitches, but somewhere between him and Ottavino the call to Maybin should have been changed. Ottavino also served up a slider that Amarista hit for the homer, after he couldn't catch up to a fastball the previous pitch.
Rockies left fielder Carlos Gonzalez extended his hit streak to nine games with a single during a two-run eighth that also included a Jordan Pacheco RBI single and a Chris Nelson RBI double.