Cueto allowed eight hits and three earned runs, struck out four and picked off three runners at first base.
He said he's ready to start the 2016 season with his new teammates and help them to another even-year championship.
Giants manager Bruce Bochy said he's been "slow-playing" Cueto as he shook away the offseason rust. But it was his three pickoffs that were in postseason form. Cueto allowed just three stolen bases last season in 212 innings.
"I don't remember ever picking off three guys in a game before," Cueto said through an interpreter. "I just try to throw the ball to the left hand of my first baseman and where the runner is going to be. But, yes, I'm a good dancer."
Cueto also helped himself at the plate with a sacrifice bunt and an RBI single in the second inning to take a 3-2 lead, one the Giants would not relinquish. The Giants had 13 hits, including home runs from Buster Posey, Brandon Belt and Brandon Crawford. Posey went 2-for-3 with a pair of RBIs. Ehire Adrianza was also 2-for-3 with an RBI.
Sacramento took a 2-0 lead off Cueto in the top of the second inning when Hak-Ju Lee wrapped a shot around the right-field foul pole. Lee played 37 innings for the Giants at shortstop this spring before being sent to Sacramento; he started Wednesday for the River Cats at short. But the Giants answered with three runs in the bottom of the inning. Crawford's two-run blast tied it and Cueto's broken-bat single up the middle ended up being the game-winner.
"I'm definitely more relaxed at the plate," Cueto said.
Bochy said his squad is finally coming together, and just at the right time. His squad finishes Spring Training Thursday through Saturday with a three-game, home-and-home series against the Athletics. The 2016 regular season begins Monday in Milwaukee.
"We got Johnny stretched today and he pitched six solid innings. He could have thrown 120 pitches today," Bochy said. "We're coming together at the right time. We're healthy and we're ready."
The River Cats, one of the most successful Triple-A teams since their inception in 2000, agreed to a two-year affiliate deal before the 2015 season and just last week signed a four-year extension -- the longest allowed by Major League Baseball. Wednesday's game was the first between the farm team and the parent club, and the stands, as well as the grassy berm that spans from center field and wraps around the foul ball pole in right to midway down the line, were packed.
"This is a beautiful park," Bochy said. "Even Buster said how nice it was, and the guys were excited to play here. It was a nice change from the parks in Arizona and the crowd and the atmosphere was great."
Up next for the Giants: The Bay Bridge Series opens Thursday at AT&T Park against the Athletics. Jeff Samardzija will get his first home start at AT&T, opposing Chris Bassitt at 7:15 p.m. PT. Watch on MLB.TV.