Stauffer (9-12) scattered four hits and struck out six batters without issuing a walk.
"I felt good early on. I had a little extra on my arm. For some reason it was coming out better than on other days," Stauffer said.
Heath Bell pitched a perfect ninth to earn his 38th save of the season
Wade Miley (3-2) went six innings in defeat, giving up two runs on five hits while fanning three and walking three.
Arizona saw its lead in the NL West fall to six games as the Giants defeated the Rockies on Friday.
The Padres plated both of their runs in the first inning. Bartlett slapped a one-out single and advanced to second on a wild pitch by Miley. Guzman followed by driving home Bartlett with a single to left and a double by Nick Hundley, coupled with an error by Gerardo Parra, allowed Guzman to score from second.
"I wasn't very effective in the first inning. I got behind guys and wasn't making good pitches," Miley said.
Arizona put a runner into scoring position in the third when Bloomquist smashed a two-out double into the left field corner, but he was stranded there as Parra struck out, putting a halt to the scoring opportunity.
The Diamondbacks wasted a leadoff double by Young in the fifth as he was erased on a fielder's choice by Lyle Overbay and Ryan Roberts grounded into an inning-ending double play to keep the shutout intact.
Justin Upton beat out an infield single in the seventh and Young ripped a sharp single into left to put two runners on with two outs. Overbay grounded out to end the frame.
San Diego had a chance to add an insurance run in the seventh when Cameron Maybin worked a two-out walk and took second when Bryan Shaw threw the ball away on a pickoff attempt. Maybin would remain at second however, as Bartlett flied out to right to end the inning.
Prior to Friday's game, the Diamondbacks recalled outfielder Cole Gillespie from Triple-A Reno...Arizona leads the season series with San Diego by a 10-6 count...Padres third baseman James Darnell left the game in the seventh inning with an apparent injury to his shoulder...Arizona is 38-26 against the National League West, while San Diego is 22-42 against its own division.