It has to be this way, and it must be this way. Justice demands it.

It is only right and proper for all interested parties that the Giants and the St. Louis Cardinals brought this series back to San Francisco, back to China Basin on Sunday for Game 6.

If there really are baseball gods, and they are not corrupt, we will also get a Game 7 Monday night.

And it will be a one-run game in the late innings, with everybody in the ballpark, including both dugouts, holding their breaths.

If ever there was a series during which both teams have faith until the very last pitch of the very last possible game, it is this NLCS -- especially after each team has overcome so many challenges.

The Giants, you might recall, entered 2012 wondering if Buster Posey's body could handle a full season after a devastating injury. They had no one to replace closer Brian Wilson, who was sidelined for the season. They lost their top hitter, Melky Cabrera, to a drug suspension in mid-August, just before the rival Dodgers made a blockbuster move to steal the division.

Yet the Giants grew stronger down the stretch, winning the division and having the gall to bounce back from a two-games-to-none deficit on the road to beat Cincinnati in the N.L. Divisional Series.

Here they are again, after going down three games to one in St. Louis, up from the dirt and thriving.

As unlikely as San Francisco's presence might seem, the Cardinals had an even drearier outlook at the beginning of the season.

They were supposed to fade after losing longtime manager Tony La Russa to retirement and their best hitter, Albert Pujols, to free agency. And even if they withstood that, what about the loss of ace right-hander Chris Carpenter, who in July underwent surgery that sidelined him until late September?

And, oh, their No. 2 starter, Adam Wainwright, was coming off Tommy John surgery.

Yet St. Louis persevered, winning a wild-card berth and staging an astonishing late rally in Game 5 to filch its NLDS from the Washington Nationals.

The Cardinals, who rallied past Texas last October to win the World Series, are in the habit of throwing dirt off themselves and rising to have arms raised in triumph.

So wouldn't you know it, Carpenter, who returned to action only one month ago, will be on the mound Sunday in Game 6.

After delicate surgery, including the removal of a rib, the 37-year-old has not been the dominating pitcher he once was.

Advantage: Giants.

Carpenter will face a Giants team that will arrive at the ballpark, perhaps the prettiest in the world, fully aware that its best work of late has come not at home but on the road. San Francisco has won only one of four home games this postseason.

Advantage: Cardinals.

San Francisco has the more experienced manager -- Bruce Bochy has been superb this month -- and is 4-0 in elimination games this postseason.

Advantage: Giants.

St. Louis has won four consecutive postseason series against favored teams: Philadelphia, Milwaukee and Texas last year; Washington this year. The Giants opened this series as the favorite.

Advantage: Cardinals.

That crucial Game 5 bunt single by Barry Zito, as well as Cardinals pitcher Lance Lynn's throw that glanced off second base and into center field, would suggest fate is with the Giants.

That St. Louis has the edge this postseason in batting average (.244 to .216), runs (56 in11 games to 38 in 10) and earned-run average (2.78 to 3.94) would indicate the statistics are with the Cardinals.

October baseball, however, has a way of mocking statistics and fate and trends. And elimination games have a way of stumping logic.

The rosters of the Giants and the Cardinals boast not a single player who already makes a strong case for the Hall of Fame. There is no Pujols. No Jeter, no Halladay, no Ichiro. Not even a Justin Verlander, who is at least halfway to the Hall.

This NLCS is about two outstanding teams, fairly even and without a superstar presence, inviting unpredictability and the possibility of an unlikely hero.

Inasmuch as the Giants and the Cardinals each has a grind-it-out, underdog mentality, Game 6 seems so necessary and Game 7 feels so inevitable.

These teams are proven finishers. It's what they do. Neither believes it will fail. Yet one of them must. How can the battle between them be anything but epic?

Contact Monte Poole at mpoole@bayareanewsgroup.com. Follow him on Twitter at twitter.com/1montepoole.