ST. LOUIS – Some monster investments take years to yield results, but this is one for the ages.

Barry Zito saved the Giants' 2012 season.

On Friday, Zito didn't erase five dismal seasons in which his bloated, $126 million contract made him a punch line for media and fans. But his cool-as-a-pop- star display of shutdown pitching did create a new and completely redemptive turning point for his once-tortured career.

Giants 5, St. Louis Cardinals 0.

Barry Freaking Zito saved the Giants' season over 7 2/3 innings of confounding and masterful pitching that neutralized powerful Cardinals hitters all night.

Zito struck out six Cards, all of them swinging at his fluttering array of off-speed pitches that made his 84 mph fastball seem like 100. Zito's only walk was an intentional one, to set up a huge double play that got him out of a second-inning jam.

At one point, Zito retired 11 straight Cardinals while the Giants built an unlikely lead on four unearned runs in the fourth inning.

As if lifted by Zito's cool-guy demeanor, Giants fielders – who had been so wobbly on Thursday – were suddenly making highlight- reel plays all over the diamond in support of Zito.

But to illustrate what a night it was, Zito's greatest moment may have come with the bat.

The fourth Giants run was secured when Zito recognized that Cardinals third baseman David Freese was playing him deeply as Zito came to bat with two outs and Giants left fielder Gregor Blanco standing on third.

You should have heard the sounds of silence in Busch Stadium as Zito laid down a perfect bunt that Freese scrambled wildly to retrieve before throwing too late to get Zito at first as Blanco scored.

It was Zito's first bunt for a hit – ever.

The Giants dugout went wild, as did the specks of orange and black fans in a sea of Cardinals red.

Zito's signature performance as a Giant gives his team one more gasp of life to rescue a coveted shot at the World Series.

The Giants were done – again. As they were last week against the Cincinnati Reds, another National League Central powerhouse was outclassing them – again.

A Cardinals win on Friday, before 47,075 mostly rabid fans in red, would have sent the defending champions to a World Series date with the Detroit Tigers.

Cardinals ace Lance Lynn mowed down the first three Giants hitters and all seemed set for a St. Louis version of Mardi Gras.

Then all eyes turned to Zito as he strode to the Busch Stadium mound, cool as could be.

This was Barry Zito, the guy infamously left off the Giants postseason roster two years ago because he couldn't be trusted in big games.

He's still living it down. "It was certainly a huge blow just personally to be left off that roster," Zito said.

This season was Zito's first winning campaign in six with the Giants, but the skeptics were still plentiful.

How do you like him now? It wasn't hard to notice how the old hands in the Giants organization wore wondrous grins and misty eyes after Friday's big win.

"I couldn't be happier for him," said Giants manager Bruce Bochy. Former Giants owner Peter Magowan, who took so much abuse for signing Zito to seven years at $126 million, looked as happy as he's been since the Giants won it all two years ago.

"To see him come up as he did in a game like this says a lot for his character," Magowan said. "(Of his five losing seasons) It is what is. But he rose to the occasion tonight."

Now the Giants return to San Francisco with Ryan Vogelsong and Matt Cain – their other postseason aces – poised to shock the Cardinals.

To his credit, the man responsible for this Giants chance didn't gloat or express bitterness at his walking-through-hell journey to this moment. "He's a tough man," said Giants pitching coach Dave Righetti.

Entering this game the Giants had won 12 straight that Zito had started – a string that began in early August – but no one would have been surprised if Zito had taken a pratfall. He didn't.

"It's hard to sum it up one one answer. It's just a plethora of things … I've gone through with the Giants," Zito said.

"I was living pitch to pitch, moment to moment. And looking back on things, it worked out and the defense picked me up."

A 6-year-old investment, maligned by everyone, finally came through. Go figure.

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