Gonzalez, the former Padres first baseman, hit a pair of two-run homers, one coming as part of a five-run seventh inning as the Dodgers (79-55) rolled to victory all while increasing their lead in the National League West to 10 1/2 games.
The Dodgers are now 22-6 in August.
Gonzalez hit a two-run home run in the third inning off Padres pitcher Eric Stults and added another in the seventh off Anthony Bass. A.J. Ellis followed Gonzalez's second long ball with a home run of his own as the Dodgers added five runs in the frame.
The Padres are certainly familiar with the Gonzalez long ball. He hit 161 of them over his five seasons with the Padres (2006-10) before he was traded to the Red Sox in December 2011.
Stults (8-12) got Gonzalez out with a high fastball in the first inning and then tried to do the same in the third, though the results were vastly different.
"That first at-bat, I could tell he was really aggressive," Stults said. "I don't disagree with the pitch that I threw [in the third inning], but more the location."
Ryu, the burly left-hander, limited the Padres to one run over 6 1/3 innings. Ryu (13-5) allowed eight hits, one walk and had six strikeouts.
"He did a nice job of locating his fastball all night. Early on it was a heavy fastball and then he went to his secondary pitches later in the game. He's a strike-thrower," said Padres manager Bud Black.
This is not to say the Padres (60-74) didn't have their chances.
In addition to scoring their only run in the second inning they got a pair of one-out singles by Chris Denorfia and Will Venable in the third inning before Jedd Gyorko grounded into a double play.
For Venable, that was his 40th hit of the month with one game remaining Saturday.
In the seventh inning, trailing 4-1, the Padres got singles from Nick Hundley and Ronny Cedeno to start the inning. Pinch-hitter Alexi Amarista then looped a single into center field, but Hundley was thrown out at the plate on a throw by Andre Ethier.
"We had a little something going there," Black said. "But Ethier made a nice throw to get Nick. We just couldn't get a big hit there."
Relievers Carlos Marmol and Paco Rodriguez got the final two outs of the inning to protect the lead.
The Padres' first run came Jesus Guzman looped a one-out single to left field with one out in the second inning. Logan Forsythe, starting at third base in place of Chase Headley (stiff back), knocked in a run with a double to the gap in left-center field.
Headley missed his second game after experiencing back spasms in Tuesday's loss to the D-backs. He'll likely return to the starting lineup on Saturday.
The Dodgers came back to score twice in the bottom of the second inning as Ryu had an RBI double and scored on a run-scoring single by Puig. Ryu's slide into the plate was, well, interesting.
"It was really embarrassing," he said.
Stults allowed four runs on eight hits in 5 1/3 innings. He had no walks and three strikeouts.
"I think that the results were frustrating for me," Stults aid. "I gave up some hits, but felt better then the results."
Puig had three singles, a double, two stolen bases and one RBI. It was the second four-hit game of his young (77 games) career.
"He was good. He got us going early, and guys just kept swinging the bats. He was good tonight, really good," said Dodgers manager Don Mattingly.
San Diego first baseman Yonder Alonso left the game after suffering an injury to his right hand in the seventh inning. He was replaced by pinch-hitter Reymond Fuentes in the eighth.
Black said Alonso was sore and that the team would know more about his condition on Saturday. Alonso missed 34 games earlier this season after fracturing a bone in his right hand.
Former Padres pitcher Edinson Volquez, released by the team on Wednesday, signed with the Dodgers on Friday and made his first appearance against his former team in the eighth inning. He allowed a double to Gyorko to start the inning but retired the next three batters that he faced.
The series continues at 6:10 p.m. PT on Saturday.