Wainwright had retired the first 11 Dodgers before Ethier's shot to left-center tied the game and he allowed the first baserunner into scoring position in the eighth inning, taking a 2-1 margin into the ninth and apparently knotting the series at a game each.
The right-hander limited the Dodgers to a pair of harmless singles through eight innings and left with a 2-1 lead.
Manager Tony LaRussa carefully choreographed the ninth inning, using left-hander Trevor Miller to get Ethier on a popup and the inserting his stopper, right-hander Ryan Franklin to get Manny Ramirez on a fly ball to center field.
When Franklin induced James Loney to line out to left field, the money seemingly was in the bank and the two teams would move to St. Louis on Saturday for he middle two games of the series.
But Matt Holliday, who homered off young Clayton Kershaw in the second inning to give the Cardinals a 1-0 lead, had the ball glance off the heel of his glove and smack him in the stomach, dropping to the ground and allowing Loney to take second base.
"I didn't see the ball," Holliday said. "Obviously, I can catch a ball that's hit right at me. It's very difficult to swallow and it was unfortunate that it happened when it did."
Holliday, who was acquired from Oakland in a July trade, hit .355 for the Cardinals over the final 53 games of the regular season to help St. Louis to the N.L. Central pennant and had committed one error with the Cardinals.
Third baseman Casey Blake fouled off a number of pitches and earned a game-changing walk. Second baseman Ron Belliard wasn't interested in fouling off anything and rammed a single into center field to tie the game at two each as the Dodger Stadium crowd went wild.
It seemed up to Russell Martin, but a wild pitch bounced away from Yadier Molina and the runners moved up to second and third. LaRussa walked Martin to load the bases and Dodgers manager Joe Torre countered with 37-year-old Mark Loretta to hit for relief pitcher George Sherrill.
Loretta was 0-for-15 against Franklin and he fouled off the first pitch down the third base line.
Then he caught up with a fastball, low and inside, hitting it on his fists but with enough lift to clear he infield and it dropped in front of a helpless Colby Ramus in center field, scoring Blake with the winning run and resulting in a wild celebration around Loretta.
"I did know the numbers," said Loretta. "I really didn't have a lot of nerves. I felt like all the pressure was on them at that point. I was fortunate to find a little bit of fairway out there."
The Dodgers, in their own unique fashion, with their 22nd come-from-behind rally had topped Chris Carpenter in the first game and had, if not actually beaten Wainright, had held on long enough to craft an improbably rally against the Cardinal bullpen.
Wainright had led the National League with 19 wins, struck out seven and walked one.
Young Clayton Kershaw, pitching in his first post-season game, had doggedly battled the Cardinals, allowing Holliday's home run in the second and brushed off leadoff hits in the third, fight and sixth without a run being scored.
In a remarkable gesture of faith, Torre allowed him to work the seventh inning and the pitch count caught up with him. He gave up another leadoff hit, this one a single to Mark DeRosa, and a booming double off the base of the center field wall by Rasmus to drive in DeRosa and give the Cardinals a 2-1 lead.
Rasmus was nailed attempting to stretch the double into a triple, with Matt Kemp throwing the ball to Rafael Furcal who fired to the plate. James Loney cut it off and drilled DeRosa at third base, much to the dismay of LaRussa who almost threw his cap onto the floor of the Cardinals dugout before disappearing down the runway toward the St. Louis clubhouse.
Carpenter popped up before one-time Dodger Julio Lugo singled sharply to center, a hit that would have given the Cardinals a 3-1 margin.
Ron Belisario ended the seventh inning, retiring Branden Ryan on a fly to center.
Torre put stopper Jonathan Broxton into the game early and he worked a 1-2-3 eighth and George Sherrill, he eventual winner, retired the Cardinals in the ninth, working around a one-out single by DeRosa, his fifth his of the series.
Then came the remarkable rally in the ninth, one that put Loretta's name in the Dodgers memory book for all-time.
"Nobody ever gives up," Loretta said. "That's sort of been our mode this year. We won our first 13 at home, we had a bunch of these last-minute wins, so it obviously gives us some confidence in that situation.
"This is the best moment of my career," Loretta said.
Kershaw allowed nine hits and two runs in 6.2 innings. He struck out four and walked two.
Torre had compared Kershaw with the greatest Dodger pitcher of all-time, Sandy Koufax. "I know it is unfair to saddle him with that," Torre said. "But he has that same look in his eyes that Koufax had. It's something I have never seen in a pitcher so young."
The two big sluggers in the game, Albert Pujols and Manny Ramirez, were just immaterial in the game. Pujols had a single and a walk in four trips to the plate and Ramirez was 0-for-4. Pujols is 1-for-6 and Ramirez 1-for-8 after two games.
After taking today off, the two clubs will move to St. Louis for the third and fourth games, with Vincinte Padilla drawing the nod for Los Angeles.
Speaking for Dodgers fans everywhere, third base coach Larry Bowa told Manny Ramirez "I can't figure this game out," as they walked out of the Dodgers' clubhouse together.
Score by innings St. Louis 010 000 100-2 Los Angeles 000 100 002-3 Los Angeles ab r h bi ave Furcal ss 3 0 1 0 .571 Kemp cf 4 0 0 0 .111 Ethier rf 4 1 1 1 .429 Ramirez lf 4 0 0 0 .125 Loney 1b 4 0 0 0 .250 Pierre pr 0 1 0 0 .000 Blake 3b 3 1 0 0 .286 Belliard 2b 4 0 1 1 .286 Martin c 3 0 1 0 .200 Kershaw p 2 0 0 0 .000 Belisario p 0 0 0 0 .000 Broxton p 0 0 0 0 .000 Thome ph 0 0 0 0 .000 Hudson pr 0 0 0 0 .000 Sherrill p 0 0 0 0 .000 Loretta ph 1 0 1 1 1.000 ------------------------------------------- Totals 32 3 5 3 St. Louis 34 2 10 2 HR- Ethier (1), RBI- Ethier (1), Belliard (1). LOB- Los Angeles 7, St. Louis 7. RISP- Los Angeles 2-for-3, St. Louis 0-for-9. DP- Furcal, Belliard and Loney. Los Angeles in h r-er bb so era Kershaw 6.2 9 2-2 1 4 2.70 Belisario 0.1 0 0-0 0 0 0.00 Broxton 1.0 0 0-0 0 0 3.86 Sherrill (1-0) 1.0 1 0-0 0 0 0.00 WP- Kershaw. HBP- Thome. T- 3:07. Att- 51,819.