Stults (6-15) turned in a solid performance, allowing two runs on five hits over six innings, but he was outdueled by Hyun-Jin Ryu, who was activated from the disabled list prior to the game.
"The results were good," Stults said of his effort. "I felt like my command was a little off today, but I made some pitches when I needed to. Unfortunately, we came up a little short today. But, overall as a pitcher, you go out and battle and give your team a chance to win, that's a good day."
Ryu (14-6) tossed seven innings while yielding one run on four hits coming off a hip strain that sidelined the left-hander for two weeks. He struck out seven and did not walk a batter.
"He's got a four-pitch mix," Padres manager Bud Black said of Ryu. "He's a strike thrower, holds runners, fields his position -- he's a truly complete pitcher."
In four starts against the Padres this season, Ryu has gone 3-0 with a 0.69 ERA and 26 strikeouts against just four walks.
The Padres kept the game close, trailing by just one run going into the eighth. But, Los Angeles scored four times in the inning against Blaine Boyer and Alex Torres to put the game out of reach.
Juan Uribe hit a bases-loaded single over a drawn-in infield to plate Adrian Gonzalez, who had four hits in the game. Matt Kemp later scored on a wild pitch, and Darwin Barney hit a two-run single to give the Dodgers a 6-1 lead.
Jesse Hahn allowed a run-scoring double to Uribe in the ninth as Los Angeles extended the lead to 7-1.
Two of the Dodgers' runs came as a result of bloop hits to the outfield. In the first, Yasiel Puig hit a pop fly that dropped in between second baseman Jedd Gyorko and right fielder Rymer Liriano, who appeared to lose the ball in the sun. Puig later scored on a single by Scott Van Slyke.
"That's the way it goes," Stults said. "Sometimes the hard ones get caught, and when you make good pitches, those ones fall in. It was just one of those days where it was a battle."
San Diego evened the score in the bottom of the inning on a double by Yasmani Grandal just past the dive of first baseman Gonzalez that scored Yangervis Solarte.
It was Solarte who, in the fifth, could not glove a pop up off the bat of Gonzalez that allowed Hanley Ramirez, who had walked, to reach second base. Ramirez then scored on a single by the next batter, Kemp, that gave the Dodgers a 2-1 advantage.
"[Stults] really deserved a better fate," Black said. "He wasn't pinpoint, but his misses weren't plentiful. We had a fly ball that we misplayed, and then the ball hit by [Gonzalez] that kind of fell into the Bermuda Triangle and we just couldn't get to it."
Despite dropping the series finale, Black spoke highly of his team's efforts over the weekend.
"It was a great series," Black said. "Two walk-off wins against a first-place team, and we were right there today in the eighth inning. We just couldn't muster any offense against Ryu, and they strung some hits together against three of our guys. Overall, it was positive."
The loss was the Padres' sixth in their last 25 games at home, which is the best in the Majors over that stretch.