* Dodgers blast four homers to avoid elimination
* Force a Game Six in St. Louis
* Greinke pitch perfect after a rocky start (Adds detail, quotes)
By Mark Lamport-Stokes
LOS ANGELES, Oct 16 (Reuters) - Pitcher Zach Greinke survived a shaky start before dominating and Adrian Gonzalez powered two homers as the Los Angeles Dodgers beat the St Louis Cardinals 6-4 on Wednesday to stave off playoff elimination.
With their backs to the wall going into a must-win Game Five at Dodger Stadium, the home team's offense sizzled in bright afternoon sunshine as they trimmed the Cardinals' lead to 3-2 in the best-of-seven National League Championship Series.
Left-hander Gonzalez set the tone with his first home run in the bottom of the third before adding a second in the eighth, while Carl Crawford and A.J. Ellis also weighed in with huge blasts to keep St. Louis under continual pressure.
Former Cy Young winner Greinke initially struggled on the mound but dug his way out of a jam in the top of the first with bases loaded and no outs, striking out Matt Adams and getting Yadier Molina to ground into an inning-ending double-play.
"That was big," Greinke told reporters. "I was real nervous out there with that situation and trying to make a good pitch and get Adams to chase and get him into a double-play.
"And then Molina, I know if you hit on the ground there is a good chance it's either going to be a hit or a double-play. Risky going in, bases loaded, because he could do some damage.
"He can adjust to anything and I kind of got lucky, I guess. I made a good pitch but still even with a good pitch he can hurt you. It just worked out."
After enduring two rough innings to start, Greinke reverted to his usual dominance, allowing just two runs and six hits while striking out four and walking one in seven innings pitched.
The Los Angeles batters took control in the bottom of the second, sparking thunderous roars at Dodger Stadium with RBI singles from Juan Uribe and Greinke as they opened up a 2-0 lead.
Carlos Beltran and Matt Holliday each drove in a run to tie the score in the top of the third for St. Louis before Gonzalez blasted the first homer of the afternoon to right field in the bottom of the inning to put the Dodgers ahead 3-2.
Crawford kept the power surge going for the Dodgers, hitting a massive homer 447 feet into the right-field pavilion in the bottom of the fifth, and Ellis followed suit with another blast in the bottom of the seventh.
"The pitching has been dominating this series, and nobody's been hitting home runs," said Crawford, after hitting his fourth homer of the postseason.
"Today we just seemed to find the stroke for the home run. I don't really know why that is, but we'll take it."
Greinke was given a standing ovation by the Dodgers fans as he headed toward the team dugout after pitching a perfect seventh inning, and Gonzalez triggered more cheers with his homer on a line drive to right field in the eighth.
Adams singled on a line drive for Holliday to score in the top of the ninth but it was too little too late for the Cardinals, who have twice lost the National League Championship Series after establishing 3-1 leads.
St. Louis starter Joe Kelly, who pitched impressively to win a marathon Game One, did not fare as well on Wednesday, allowing seven hits and four runs while striking out three in five innings.
"We had a couple opportunities to do something, and just couldn't make it happen," said Cardinals manager Mike Matheny. "Those usually come back to haunt you, and today they did.
"You're going to have games where you just can't make it happen, and we've got to figure out a way to get it done the next time we get a chance."
Game Six is in St. Louis on Friday when the Cardinals, who won the most recent of their 11 World Series titles in 2011, will start with rookie Michael Wacha while they have to contend with ace Dodgers pitcher Clayton Kershaw.
"Obviously I didn't like being down 3-1, and now I'm not necessarily thrilled about having another elimination game," said Dodgers manager Don Mattingly.
"But I feel pretty good about having Clayton pitching on Friday night and our chances of getting a seventh game." (Reporting by Mark Lamport-Stokes; Editing by Frank Pingue/Nick Mulvenney)