The win was the fourth in a row for the Padres (5-2), who lead the National League West as they head off on a nine-game road trip beginning Monday night in New York against the Mets.
Young retired the first 12 batters he faced and wound up allowing just four singles and one unearned run in seven innings. He struck out seven and walked one as he improved to 2-0 on the season. He didn't win his second game last year until his sixth start.
Hundley was working on a natural cycle after he singled, doubled and tripled in his first three at-bats. He came to the plate in the seventh needing a home run to become the first Padres player to hit for the cycle in their 40-year history. He ended up with an RBI single and finished with a career-high four hits.
"C.Y. gave us a great feel to that game early on, how he pitched very efficient," said Padres manager Bud Black. "He didn't allow a baserunner until the fifth [Bengie Molina's leadoff single]. You need that against a guy like [Tim] Lincecum. You know his history against us is such that I'm sure he has a lot of confidence."
Lincecum (0-1), the NL Cy Young Award winner who gave up four runs on 10 hits in 5 1/3 innings, came into Sunday's game having held San Diego scoreless over his last 24 innings. He had given up just one run in 23 1/3 innings over his last three outings here at PETCO Park.
"But our guys early on, even prior to the game, had a sense that it was going to be a little different today," said Black. "And our guys had some good at-bats."
Two of the key at-bats came in the third inning. With two out and Jody Gerut on third after doubling, Adrian Gonzalez lined a single to left scoring Gerut with the first run of the game. Chase Headley then followed with his second home run in two days, a drive that landed in the short porch in right field, and suddenly it was 3-0, Padres.
"Gonzo gave us a little lift with his hit and Chase gave us a bigger lift," said Black.
Headley was asked about the Padres' 5-2 week to start the season and whether he thought they were shattering expectations.
"It doesn't really matter what anybody else thinks, it matters what everybody thinks in this clubhouse," said Headley, "and I think everybody in here believes we can win."
"It's a long season, but we're off to a good start as a team," said Young, who also had one of the 10 hits off Lincecum. "I think this was a good homestand for us. I think the guys had a lot of confidence. I think we realize if we play the right way and go out and play hard night in and night out for nine innings, we can compete with good teams.
"Our defense has been awesome," added Young. "They have made great plays and have made the routine plays, and that's huge. In this ballpark you have to win with pitching and defense."
And of course, hitting doesn't hurt, either.
Hundley said he was aware he had a chance at the cycle when he came to the plate in the seventh inning, but he wasn't cognizant of the fact that no Padres player had ever hit for the cycle. His manager wasn't aware of either situation.
"Obviously I thought about it after the triple, but you try not to let it [affect you]," said Hundley, who singled in the second, doubled in the third and tripled in the sixth. "I didn't know that no Padre had hit for the cycle until after the game. I'm glad I didn't know that.
"All I wanted to do there in the seventh was go up there and get a good pitch to hit," said Hundley. "I tried not to do too much because I could get myself in trouble. It was a good pitch to hit. [Giants reliever Jeremy] Affeldt has great stuff. You just want to get him in your zone and get something I could handle.
"I don't think I had ever had three hits in a Major League game, let alone four," said Hundley. "We feel good about sweeping a team like the Giants. We know it's early and we have a long way to go, but we're going to play hard every day, play hard for nine.
"When you have guys like C.Y. throwing a game like that, he gives you a chance to win every single game."
Sandy Burgin is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.