Ryu threw six strong innings and the Dodgers beat the Padres 2-1 Sunday soon after San Diego's general manager Josh Byrnes was fired.
Ryu (9-3) had few problems against the light-hitting Padres, as he won for the sixth time in seven starts since missing more than three weeks with shoulder inflammation.
"I try to be aggressive in every ballpark that I pitch in," Ryu said through a translator. "Today, I think the main thing was ball control. I was able to keep the ball down early and that was the story."
The Dodgers, winners of 10 of 14, took two of three games in the series and have either won or split their last 11 series in San Diego. The last time they lost a series in San Diego was a three-game sweep in September 2010.
"It felt good to get this series," Los Angeles manager Don Mattingly said. "We got a couple of runs early and you'd like to keep tacking on. Hyun-Jin was throwing the ball good and our bullpen did a nice job to held on for the series."
The left-handed Ryu gave up one runs and four hits, and he did not allow San Diego to get its first hit until the fourth inning.
"He got off to a good start," said Dodgers catcher A.J. Ellis. "He kept them off balance the first time through the lineup. They made some good adjustments, made him throw more in the middle innings."
In three career starts against the Padres, Ryu has allowed only two earned runs in 19 1/3 innings.
Byrnes had been San Diego's GM since October 2011. The Padres went 76-86 in his first two seasons and are 32-44 and 13 1/2 games back in the NL West this season.
Ryu helped himself in the second when his sacrifice bunt advanced Scott Van Slyke and Ellis. Gordon drove in Van Slyke with an RBI single to right but Ellis was thrown out at home by right fielder Chris Denorfia.
Denorfia had two hits off Ryu, including a leadoff double in the sixth. After a groundout advanced him to third, Denorfia scored on Carlos Quentin's groundout.
Mattingly decided to pull Ryu after the sixth because he sensed his starter was getting tired.
"I would like to go deeper in the game but toward the end, I felt a little bit extra more fatigue," Ryu said. "After talking to Donnie about it, he made the call."
Said Ellis: "It was typical Hyun-Jin. He gave us a chance to win the game. He makes big pitches when he has to. He comes to win."
Stults rebounded from a string of six straight subpar starts as he allowed two runs on six hits in a season-high seven innings. He struck out five and walked three. It was just the second time in 24 starts that the lefty has walked more than two batters.
"Location was better," Stults said. "I was able to limit the mistakes and was just able to kind of keep them off balance."
Stults has lost seven consecutive decisions over eight starts. The last time he won was a 6-2 victory over Miami on May 10.
Dodgers LF Matt Kemp extended his hitting streak to 10 games, while Ramirez increased his to nine games. ... San Diego has scored 23 runs in Stults' 16 starts. ... Padres 3B Chase Headley (back) missed his fourth straight game. ... Dodgers RHP Zack Greinke (9-3, 2.57 ERA) faces Royals RP Jeremy Guthrie (4-6, 3.86) Monday in the opener of a three-game series at Kansas City. The Padres travel to San Francisco on Monday with RHP Andrew Cashner (2-6, 2.36) squaring off against Matt Cain (1-3, 3.66).