ST. LOUIS — Uh oh.

The intangibles are really the only edge the Chicago Blackhawks have left over their rivals of nearly a half century. The St. Louis Blues‘ lineup is deeper, bigger and fresher after several springs of first-round exits.

Simply put, on paper St. Louis is better. Unless that paper is a brain scan, where the Blackhawks’ supreme confidence trumps the Blues’ head trash by some margin.

Then, this.

After the Blues stormed back to tie the game in the third period, then absolutely dominated the first overtime session, Patrick Kane checks in with his first goal of the series at 3:07 of the second overtime period. Chicago wins 4-3.

The Blackhawks aren’t dead yet.

Neither are the Blues deepest fears — that they might choke in the playoffs… Again.

“The Hockey Gods are testing us right now,” said St. Louis defenceman Alex Pietrangelo, an absolute stud in this one with three assists in 39:49 of ice time. “I still thought we deserved to win the game. The puck ends up right back on (Kane’s) stick somehow, and he finds an open net. I thought we … played one of our better games tonight.

“It’s going to be fun to win it in Chicago,” he added. “That’s the game plan right now. Their backs are still up against the wall.”

Of course it was Kane who exhumed the Blackhawks’ season on a wrap-around goal. He’s Mr. Clutch, with his fifth playoff overtime marker, tying him with former Edmonton Oiler Glenn Anderson for third on the all-time list.

“I don’t think I was very good in the first overtime or very good at all tonight,” said Kane, who had just one shot on goal through the first four periods. “It was one of those things I try to tell myself to play with confidence going into that fifth period and try to make some plays. I was able to do that a couple times. Fortunate enough that puck squeaked to the side there.”

It is the storyline that Blackhawks Nation hoped would unfold: The experienced, never-say-die Hawks draw on a well deepened through three Stanley Cup wins, their biggest stars refusing to let a season end in the Missouri barn of the hated Blues.

Chicago’s stats in these games are uncanny; numbers that tell you what resilient champions these Blackhawks have truly been:

• Chicago is now 12-3 in elimination games since 2010.

• In two of three series Chicago has lost, they stretched the series to overtime in Game 7.

• And they’ve never lost the first elimination game in a series. It always takes a few tries to kill these guys off.

How do they thrive when the pressure not to lose is the highest?

“I don’t know,” Kane said, shaking his head. “I’ve played in a lot of overtimes with this team; had some long stretches here in playoff runs. I think in the past with our team it seems like it’s kind of like the next guy up; it’s someone else’s turn.

“Maybe it was my turn to step up tonight and do something there in overtime which I’ve been waiting a lot longer than I should. It’s a good feeling, keeps us alive, go back home now and it’s going to be exciting playing a Game 6 in our building.”

Chicago broke the game open in the second to take a 3-1 lead after 40 minutes, but the Blues roared back to tie it in the third. They were by far the better team in the first overtime, but the task of finishing off the Blackhawks is perhaps the great bogeyman in hockey today.

It simply wasn’t going to be a five game series between these two clubs, in the only Round 1 series that features two Top 5 teams from the NHL’s regular season. The Blues will have to try and go 3-0 at the United Center after winning Games 3 and 4 there.

Come to think of it, what are the chances Chicago loses three games at home in the same series? This has a return to St. Louis for Game 7 written all over it.

What did Blues head coach Ken Hitchcock say to his players after the game?

“The plane’s at three. Let’s get playing,” he said. “We knew this was going to be difficult. We knew this was going to be hard and we knew it was going to be a huge challenge. We’ve just got to find another way to make them crack some more.”