It's only the second time in franchise history, and the first since 1975, the Padres won while getting one hit.
San Francisco, which dropped into a first-place tie with San Diego, probably won't experience a more frustrating defeat all season.
The Giants, who have scored three runs in their past 30 innings, lost their third straight game by one run.
"You are going to have these days when you are going to lose 1-0," Sanchez said.
"I haven't been in a game like this — one hit and you come away with a loss," Giants manager Bruce Bochy said. "To have that many opportunities, it's tough to do.
"They are very upset," Bochy said of his players. "There’s no way we should have lost tonight's game."
It's happened before, though infrequently, a team winning with just one hit. Two seasons ago, the Dodgers were no-hit by the Angels and still won.
Sanchez (right) got beat, not only for of a lack of Giants offense, but also because the Padres had the perfect small-ball inning.
Chase Headley(notes) led off the fourth with a single and stole second base. Kyle Blanks(notes) hit a foul pop that Aubrey Huff(notes) caught as he tumbled into a camera well, allowing Headley — who had tagged up — time to reach third base.
"Not a typical win, but it's just as valuable as scoring 17," Headley said, referring to San Diego's home-opening, 17-2 win against Atlanta on April 12.
David Eckstein(notes), one night after winning the game with a home run, saved a run in the fourth inning with a great diving catch to bail out starter Mat Latos(notes). It just was not the Giants' night. Again.
- San Francisco