Shields became the first Padres starting pitcher to begin a season with a 6-0 mark since 1985 - when Andy Hawkins began that season with an 11-0 record on his way to an 18-8 finish.
But to insinuate that Shields, staked to an 8-0 lead after two innings, coasted, would be wrong.
"It might sound funny, but when you get eight runs early, in two innings, it's a little tougher to pitch," said Padres manager Bud Black. "But he kept his concentration and kept his edge. He gave us what we needed, six straight zeroes."
Shields' outing Sunday was the sixth consecutive game a Padres starting pitcher has compiled a quality start. All told, he allowed three runs -- all in his final inning, the seventh. He threw only 79 pitches and got seven ground-ball outs.
Shields has benefited this season from a surplus of run support, as the team has averaged 7.65 runs per start.
"I don't know what it is, to be honest with you. I guess it's just luck. I think this is a good hitting team, we're just in a rut right now," he said. "… Hopefully the pitching staff continues to throw quality starts like we are. If we keep that going, we're going to win a lot of series with pitching."
Shields took a one-hit shutout into the seventh inning Sunday and did so by having thrown only 61 pitches, which rated as efficient as he's been all season.
"I threw a lot of fastballs today. I mixed up my pitches pretty well," Shields said. "Maybe kind of half and half of everything [fastballs and curveballs]. As long as I get outs, I don't really care what I'm throwing."
He loaded the bases with no outs but got Andre Ethier to bounce into a 4-6-3 double play. But before he could escape the inning, Alex Guerrero hit a two-run home run. He left after just 79 pitches, as Dale Thayer and Shawn Kelley finished the game.
Shields allowed five hits, one walk and had seven strikeouts. He leads the National League in strikeouts (82).