St. Louis Blues coach Ken Hitchcock knows a lot about this type of playoff series. The emotion. The grinding. Those tense minutes that turn ordinary stomachs but give the longtime coach pleasure.

He said he’s been through them before with Dallas. And probably Philadelphia, too.

“It’s kind of fun to be honest with you,” Hitchcock said. “In a sick way.”

His Blues pulled out another heart-stopping win Saturday to take a 2-0 lead over the Chicago Blackhawks in their Western Conference quarterfinal series.

After Ryan Miller’s shutout streak ended in a hail of deflected shots off the sticks of Chicago defensemen, one of the goal-scorers took what could be a series-changing penalty, and Hitchcock’s Blues pounced.

Brent Seabrook’s charging major for a check on Blues center David Backes led to Vladimir Tarasenko’s tying goal with 6.4 seconds left in regulation, and Barret Jackman scored 5:50 into overtime to give St. Louis a 4-3 win over Chicago in Game 2.

The Blues seem to be following a script.

In Thursday’s series opener — the longest game in franchise history — Jaden Schwartz scored the tying goal with 1:45 left in regulation and Alexander Steen won it 26 seconds into the third overtime.

The Blues now have a commanding hold on the best-of-seven series heading into Monday’s Game 3 in Chicago, though Miller said he knows it’s been a lot closer than that.

“The way these games have gone, you have to respect the fact that Chicago was a shot away in both of these games, too,” said Miller. “That’s the weird part about hockey.”

Chris Porter and Kevin Shattenkirk scored to give the Blues a 2-0 lead in the first period and Miller ended with 25 saves.

Miller’s shutout streak of 119 minutes and 27 seconds since allowing three goals on seven shots in the first period of Game 1 was snapped when Duncan Keith scored with 2:35 left in the second period to get the Blackhawks on the board.

Seabrook and Michal Rozsival beat Miller 1:45 apart in the third period to give the Blackhawks the lead, but the defending Stanley Cup champions were done in by Seabrook’s game misconduct with 4:51 left in regulation.

Skating near full speed, Seabrook checked Backes in the face with his right shoulder, sending him head-first into the corner boards and sparking a scrum between the teams as Backes tried to get back on his feet.

All Hitchcock would say about Backes was that he was “not good.”

The Blackhawks killed off an initial 46-second 5-on-3 and were seconds from escaping with the win before Tarasenko beat Corey Crawford to the near side with a long shot from above the right circle.

“You’re right there — six seconds away,” Blackhawks coach Joel Quenneville said. “The other game was tough losing it with a buck and change (left) but today was brutal.”

Quenneville declined to comment on Seabrook’s hit and the game misconduct, saying he hadn’t “analyzed it” yet and was more worried at the time about the penalty kill.

“It was amazing how we got ourselves back in this game,” he said. “We did everything we could to win the game and did a lot of right things. … There were a lot of positives to take out of this game.”

Jackman’s winner from the left boards squirted in between Crawford’s legs with Max Lapierre creating a screen in front. It was a dramatic momentum change after the Blackhawks had taken the lead in a game the Blues had seemingly controlled.

Of course, St. Louis was in the same position last year with a 2-0 lead against Los Angeles and lost the next four games.

“We gotta stay on our toes,” said Jackman. “We’re going into a tough building to play in in Chicago. It’s going to take everybody. Tonight we got a little bit lucky. We let our foot off the gas. They got a couple lucky bounces but you got a team down 2-0 you gotta finish them.”

Keith’s point shot late in the second was re-directed by a Blues player before going past Miller — a scene that played out two more times on Seabrook and Rozsival’s goals.

Seabrook’s shot fluttered past Miller after hitting Porter, and Rozsival’s knuckler started high and was re-directed low by another St. Louis player. On replays, it looked more like an MLB curveball than an NHL slapshot.

Earlier, Porter scored 7:08 into the game from a sharp angle on the left side after Crawford let a long rebound go on Jordon Leopold’s slap shot.

Steve Ott got loose for a short-handed breakaway after Keith and Patrick Sharp collided on a Blackhawks power play, but Crawford made a pad save.

Later, Crawford made a point-blank glove save on Schwartz in the final seconds of the first period, but Shattenkirk buried a slap shot from the point right after that to give the Blues a 2-0 lead.

“Both teams battle like crazy,” said Hitchcock. “We’re lucky; we’ve held serve. And now we have to take it into Chicago and see if we can get a win.”