It is the fourth time in 10 years the Cardinals will compete in the Fall Classic, while a 25-year wait goes on for the Dodgers, whose pitcher Clayton Kershaw was in woeful form.
Kershaw came up against rookie Michael Wacha for the second time in the series and it was the latter who once again walked away with the victory after doing so in game two.
Kershaw surrendered seven runs on 10 hits and appeared to capitulate after conceding a four-run third-inning, which gave the Cardinals an ideal platform to wrap up a 4-2 series victory.
Matt Carpenter's one-out double was the catalyst for the Cardinals' charge, with Carlos Beltran singling him home.
Kershaw was then taken out of the firing line in the fifth inning after the first three batters reached on two singles and a double, with the Cardinals making five runs despite not managing another hit.
The Cardinals will face the winner of the American League Championship Series between the Detroit Tigers and the Boston Red Sox, who currently lead the best-of-seven series 3-2.