Ryu allowed just one run in his six innings and left with a 2-1 lead. J.P. Howell retired all four batters he faced, Brian Wilson got the final two outs of the eighth inning, and Kenley Jansen struck out the side to record his second save in as many days to preserve the win.
"Today was as good as I've caught him all season long," catcher A.J. Ellis said of his closer. "When the ball is pretty much down the middle of the plate and you're getting swings and misses, you're pretty dominant."
The bullpen retired nine of their 10 batters faced.
"It's awesome, it's a unit," Howell said. "It's a process we have to go through and we all feel secure."
For Jansen, it was his first time pitching on three consecutive days this season, and first since Aug. 31 - Sept. 2, 2013.
"[Jansen] came in feeling good. He played catch and felt great," manager Don Mattingly said. "If we would have had any reservations we wouldn't have sent him out there."
The Dodgers are 9-0-2 in their last 11 series at Petco Park, dating back to 2011, and have won both series in San Diego this season.
Ryu has been simply sublime on the road this season, allowing nine runs in eight starts, a 1.62 ERA, with 41 strikeouts and 12 walks. Of his 50 road innings in 2014, 45 have been scoreless.
"It was typical Hyun-jin, gave us a a big chance to win this game," Ellis said. "He's a big-game pitcher who knows how to pitch to win."
The first nine batters were set down in order by Ryu, but his bid for perfection ended with a line drive by Chris Denorfia that narrowly missed Ryu's head on its way to center field for a single. Ryu got out of that jam and didn't allow a run until the sixth, when Denorfia's lead off double was cashed in by a pair of ground outs.
Thursday's off day gave every member of the starting rotation an extra day of rest this time through the rotation, which has usually equaled success for Ryu. In his career with exactly five days rest, Ryu is now 10-1 with a 1.95 ERA in 12 starts, with 58 strikeouts and 19 walks in 78⅓ innings.
Ryu has walked one or zero batters in nine of his 14 starts. He is 8-1 in those starts with a 2.28 ERA.
"There's nothing more I dislike on the mound than walking somebody," Ryu said, through a translator.
As they did in every game of this weekend series in San Diego, the Dodgers scored first. Hanley Ramirez singled, stole second, then advanced to third base on a wild pitch. A ground ball back to pitcher Eric Stults, a tailor-made double play ball to end the inning, turned into a fielder's choice and a wild throw by shortstop Everth Cabrera, allowing Ramirez to score.
The Dodgers plated another run in the second inning when Scott Van Slyke singled, walked and Ryu sacrificed them to second and third base. Dee Gordon drove home Van Slyke with an RBI single, but the bid for a two-run single was thwarted by an excellent throw home by right fielder Chris Denorfia to nail Ellis at the plate.
But that was all for the Dodgers against Stults, who lasted seven innings for his longest start of the year.
Gonzalez has driven in a run in four straight games.
Matt Kemp doubled off the wall in the sixth inning to extend his hitting streak to 10 games.
Ramirez, now second on the team with 10 steals, was 2-for-4 to extend his hitting streak to nine games.
Howell's four outs marked his third outing of longer than one inning this season. He leads the Dodgers with 37 appearances.
Gordon was tagged out on a ground ball up the first base line in the seventh inning. The Dodgers challenged the call but the ruling was upheld, ending the inning. The Dodgers are 12-7 this season in replay challenges.
Dodgers starting pitchers allowed four runs in 18⅔ innings during the weekend series in San Diego.
The Dodgers fly to Kansas City, where they will open a three-game interleague series against the Royals. Zack Greinke starts the opener in a park he called home from 2004-2010, while right-hander Jeremy Guthrie starts the series opener for Kansas City.
Home runs: none
WP - Hyun-jin Ryu (9-3): 6 IP, 4 hits, 1 run, 1 walk, 2 strikeouts
LP - Eric Stults (2-10): 7 IP, 6 hits, 2 runs, 3 walks, 5 strikeouts
Sv - Kenley Jansen (22): 1 IP, 3 strikeouts