Matt Cain has spent many a night hoping for the kind of run support the Giants gave their starting pitcher Tuesday night. Because of an accident in the clubhouse kitchen, Cain wasn't the beneficiary.

The right-hander cut the tip of his right index finger while making a sandwich just before the second game of a series with the San Diego Padres. Yusmeiro Petit made an emergency spot start and was given five runs to work with in the first three innings of a 6-0 win over the Padres at AT&T Park.

Cain's injury didn't require stitches and manager Bruce Bochy was confident Cain would make his next scheduled start. Bochy said Cain dropped a knife in the clubhouse kitchen after batting practice and cut himself when attempting to grab it. The half-inch cut occurred at a spot where Cain releases pitches from his hand.

"It should close up in a couple of days," Bochy said. "He should be fine."

The Giants didn't suffer Tuesday, as Petit cruised through six shutout innings, giving up just three hits and striking out four. Petit didn't issue a walk and threw 50 of 72 pitches for strikes. The club's long reliever had not pitched in eight days, but there were no signs of rust as he lowered his ERA to 2.61 in nine appearances and continued to bolster his case to join the rotation if the Giants decide to make a change at any point this season.

Cain was on the mound for 1-0 and 2-1 losses earlier this month, so naturally the lineup broke through as he watched from the top step of the dugout. Angel Pagan led off the bottom of the first with his second homer of the season and Buster Posey hit a solo shot two batters later. The Giants had not had two first-inning homers in a game at AT&T Park since July 22, 2008, when Fred Lewis and Bengie Molina went deep.