"They all threw well," said Giants manager Bruce Bochy. "Guys got in jams and they made pitches when they had to. [Jonathan] Sanchez did a real nice job for a couple of innings."
Sanchez was perhaps the most impressive as he came in after Cain for two innings and handled the middle part of the A's lineup with ease, striking out Mike Piazza and Nick Swisher.
"It is encouraging ... that's what you want to see," Bochy said. "We've got some difficult decisions, we know it, they're making it tough. In a couple of days we'll have this team set."
Kevin Corriea followed Sanchez with a 1-2-3 fifth, including a strikeout of Mark Ellis to end the inning.
Coming into Friday's action, the Giants had very few relievers with impressive ERAs. Sanchez, Scott Munter, Corriea, Brian Wilson and Brad Hennessey had ERAs over six.
Against Oakland, Munter was the only one that allowed a run.
"We came here and really showed that we're ready to start the season and that we can pitch consistently," Correia said. "It puts the team's, coaches' and everybody's mind at ease to pitch at this stadium, because this is where we play."
Quick start for Cain: Cain started on three days' rest against the A's and wanted to throw three innings, but only got through two after a pitch count of 48.
"I got a little anxious to get out there ... and got a little excited," Cain said. "Other than that, it was a good night. I felt real good."
Cain was most impressive after he allowed the first three runners to reach base in the second inning. With no outs, and the hot-hitting Travis Buck at the plate, Cain forced Buck to ground in a double play and yielded just one run in the inning.
"That was definitely a good confidence booster to get out of there in a positive way," Cain said. "Because it could have got real ugly."
Crow hops: Russ Ortiz is scheduled to make a Minor League start in Arizona on Sunday so he can have his normal rest for his first regular-season start on Saturday. ... Barry Zito spent about $3,600 for the steak and potatoes dinner that was provided for the Minor League complex in Arizona. "When you have some extra money, you can do things like that," Zito said. "Those guys are down there busting their [butts] and most of them will never get a chance to play in the Majors. I know how tough it is in the Minors."
Up Next: Matt Morris will start on Saturday against the A's Esteban Loaiza at AT&T Park. The first pitch is scheduled for 1:05 p.m. PT.