PITTSBURGH — This game was the first of a critical stretch for the Rangers, and it did not swing in their favor. 

A seven-point cushion on the Penguins in the Metropolitan Division standings dwindled to six after Kris Letang scored a power-play goal 1:38 into overtime to hand the Blueshirts a 3-2 loss Sunday night at PPG Paints Arena. 

It was the first of three games between the teams in the span of seven days, with the Penguins scheduled to come to Madison Square Garden on Thursday and Saturday.

The Rangers essentially have a miniseries on deck against the Penguins, who they knocked out in seven games in the first round of the playoffs last season. 

But it’s more than that.

It’s a stretch of games with postseason position on the line. 

Rangers head coach Gerard Gallant and a few of his players essentially said last season’s playoff series against Pittsburgh is in the rearview mirror.

They’re not thinking about it one bit.

And why would they?

Especially when the focus needs to be on finding their offensive rhythm as a team that can roll all four lines. 

That hasn’t been the case lately for the Rangers, who still managed to come away with five of a possible six points on this three-game road trip. 

“We haven’t played well,” Gallant said after the loss, in which both clubs’ mutual disdain for one another was on full display. “We admit to that. We’re still winning hockey games, too. Tonight, we still got a point against a real good team over there and we’re battling hard so. We got to be better. We know that. I think everyone in that room knows it.” 

After whiffing on a wide-open net on a power-play opportunity in the second period while the Rangers were trailing 2-1, Chris Kreider took a centering feed from Vincent Trocheck and buried it past Penguins netminder Tristan Jarry to tie the game at 9:09 of the final frame. 

With that goal, Kreider, who was said to be “unavailable” after the game, ultimately secured that one point for the Rangers. 

Equipped with new line combinations — which also changed throughout the game — but still no Ryan Lindgren, the Rangers still look to be disjointed.

Gallant sent out the same units with which the Rangers ended the overtime victory over Buffalo on Saturday, but they didn’t stick, either. 

The Alexis Lafreniere-Filip Chytil-Patrick Kane unit was bleeding high-danger chances.

Artemi Panarin is still turning the puck over at a consistent pace.

The Rangers, who were outshot for the second straight game, are not putting enough pucks on net. 

The third period was the Rangers’ most effective 20 minutes of the night.

They outshot Pittsburgh 12-8 and started playing a more cohesive team game. 

“I definitely think that was our best period of hockey since the deadline,” said captain Jacob Trouba, who continued to play his role as public enemy No. 1 in Pittsburgh with an open-ice hit on Alex Nylander that drew the ire of the Penguins and their fans. “Just fast, made some plays. We got our looks. Can be better, still, obviously, but thought it was trending in the right direction, which is good.”