St. Louis Blues' Kevin Shattenkirk, left, and Rangers' Rick Nash...

St. Louis Blues' Kevin Shattenkirk, left, and Rangers' Rick Nash battle for the puck during the first period of Saturday, Oct. 15, 2016, in St. Louis. Credit: AP / Bill Boyce

ST. LOUIS — Chalk it up as a tough 3-2 loss. But if the Rangers had stretched their third-period performance against the Blues across the entire 60 minutes Saturday night, perhaps the result would have been different.

“I don’t think we can play much better than we did in the third,” Henrik Lundqvist said after the Blueshirts outshot the Blues 15-0 in the final 20 minutes but couldn’t beat Blues backup Carter Hutton. “Obviously, they [the Blues] battened down, and waited for mistakes. It felt like we were going to tie the game, we had enough chances, he just made some big saves.”

Hutton finished with 33 saves as the Blues won their third straight to start the season.

Defenseman Dan Girardi left in the second period and didn’t return. Coach Alain Vigneault said Girardi suffered a hip flexor injury and will be evaluated today. “Seems like it’s more than day to day,” Vigneault added.

Tomorrow, when the San Jose Sharks visit, the Rangers (1-1) could turn to Dylan McIlrath, scratched for the first two games, or possibly Kevin Klein, who has not played because of back spasms.

“I thought we responded real ly well, which is a good sign, especially with all the young guys we have,” Marc Staal said. “We had three or four Grade A chances in the third.”

Leading 2-1 after 20 minutes, the Blues quickly converted a power play when Alex Pie trangelo slipped in alone from the left point. The defenseman beat Lundqvist at 2:28, just six seconds after J.T. Miller went to the box, for a 3-1 lead.

Hutton then allowed a goal 30 seconds later that narrowed the margin to a goal. Mika Zibanejad, coming down the left side and guarded by a defender, flipped a backhander that eluded Hutton for his first goal as a Ranger. But that was it for the Rangers, who outshot the Blues, 35-18.

“We took too many penalties in the second, so we couldn’t get anything going until the third” Staal said.

In a four-shot flurry early in the third, Hutton, who earned the start after an impressive preseason, according to coach Ken Hitchcock, made two saves on the doorstep, including one on Miller. Zibanejad’s wrister hit the post, and Ryan McDonagh’s backhander was stopped.

Hutton again denied Miller, this time shorthanded on a two-on-one with Michael Grabner. Hutton then stopped rookie Jimmy Vesey off a scramble

The Blues had taken an early lead when Vladimir Tarasenko, who scored 40 goals last season, took a short pass from Colton Parayko, and sped past McDonagh and beat Lundqvist stickside on the first shot he faced at 1:13 of the first period. “The way he came down on a breakaway . . . the way he shoots the puck, so accurate and so hard,” Lundqvist said, “you’d like to have a couple shots before you face that.”

Chris Kreider scored at 5:25, when Zibanejad nudged the puck toward him between the circles. But after the 8:20 mark of the second, the Blues found their legs and the Rangers sputtered. That’s when the Blueshirts had their last shot of the period on a shorthanded bid from Grabner.

Paul Stastny ducked behind Nick Holden to the right post and tucked in a loose puck that the defense couldn’t clear to restore the lead at 2-1. “There was no quit in us,” Vigneault said. But the Blues didn’t fold, either.

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