Adrian Gonzalez clubbed a RBI single to get the go-ahead run in the fourth inning and Yasiel Puig snapped a hitting slump with a two-out RBI triple just a couple of batters later as the Dodgers cut the Cardinals' series lead to two games to one.
South Korea's Ryu allowed just three hits and no runs in seven innings of work Monday night for the Dodgers who looked nothing like the wounded bunch that dropped the first two games of the series in St. Louis.
Game four of the best-of-seven series is on Tuesday.
Once Los Angeles manager Don Mattingly decided Ryu's night was complete, the bullpen did the rest in front of a sold-out crowd of 53,940 at Dodger Stadium.
Cardinals starter Adam Wainwright threw seven innings, allowing six hits and two runs. He struck out five.
Ryu also had four strikeouts and just one walk for the Dodgers who prevented the Cardinals from taking a stranglehold in the series.
Los Angeles shortstop Hanley Ramirez played through the pain of a hairline fracture in his rib and went two-for-four with an RBI.