* Burnett melts down in seven-run third
* Wainwright, pitching, Beltran power sink Pirates (Adds quotes, details)
Oct 3 (Reuters) - Carlos Beltran blasted a three-run home to launch a seven-run, third-inning outburst that carried the St. Louis Cardinals to a 9-1 victory over the visiting Pittsburgh Pirates in the opener of their National League Division Series.
Cardinals starter Adam Wainwright cruised through the first three innings retiring all nine batters, before Pittsburgh starter AJ Burnett had a monumental meltdown yielding four hits, a hit batsman and three walks to the first eight batters in the third.
"We had a rough game. Game 164 was rough," said Pirates manager Clint Hurdle, whose team won a wild card playoff game against the Cincinnati Reds to advance. "One of the things we do really well is we don't overcook things when we don't play well.
"We're down one game in the series and we'll move on."
The nightmare inning began with a walk to Wainwright and Matt Carpenter followed with a single before post-season slugger extraordinaire Beltran cleared the bases with a long, towering home run into the second deck down the right-field line.
It was Beltran's 15th career homer in the post-season, tying him on the all-time list with Babe Ruth, who belted all of his in the World Series in the days before extra levels of playoffs.
"I was looking for a pitch inside and I got it," said Beltran. "Was a great feeling.
"I've been fortunate to play in my career for the fourth time in the postseason. To be able to come through like that I really enjoy it and am happy for the opportunity."
Matt Holliday then ripped a double to right-center, Matt Adams was hit by a pitch, and a walk to Yadier Molina loaded the bases before John Jay was walked, which produced another run.
David Freese then sliced a single down the right-field line and all three baserunners scored before Burnett was removed from the game.
St. Louis added runs in the fifth and sixth, while slugger Pedro Alvarez homered in the fifth to keep Pittsburgh from being shut out.
Wainwright went seven innings, giving up one run and three hits while striking out nine with no walks, combining with Carlos Martinez and Trevor Rosenthal on a four-hitter.
The 19-game winner had command of a knee-buckling curve that kept the Pirates off-balance and made his pinpoint fastball all the more effective.
Wainwright was just as proud of the lead-off walk he worked against Burnett that got the Cardinals' big inning started.
"As a starting pitcher anything you do offensively is a bonus," he said.
"I knew right there leading off an inning I could be an automatic out and not put out any effort, or really grind him out. I was lucky to work a walk there."
"We've lost a few games like this this year," said Hurdle, said. "What we've been good at is just moving on."
St. Louis claimed a 1-0 lead in the best-of-five with Game Two scheduled for Friday. (Reporting by Larry Fine in New York, Editing by Greg Stutchbury)