This was not about the opponent, not about the way last season ended or the way this one might. For the Rangers, this was about another two points that just happened to come at the expense of the Devils, a 4-1 triumph yesterday at the Garden that eliminated their cross-river rival from playoff contention and solidified the position of the Blueshirts. “Losing last year in the playoffs and being so close, and knowing they don’t like us much either, it’s always nice to beat them,” said Brad Richards, showing resurgence with another two assists. “It was a big win for us.” In overtime of Game 6 in last season’s Eastern Conference finals, it was Adam Henrique who ended the Rangers’ season. Yet yesterday, behind two goals from captain Ryan Callahan and another solid performance from Henrik Lundqvist in nets, the Rangers (24-17-4) have made the rest of the Devils (17-18-10) season a walk-through. “They’re out now, but I don’t think that’s why we were playing,” Richards said. “We were playing because we need to stay alive.” With the win, the Rangers are tied in points (52) with the seventh-place Senators, who stay ahead by virtue of their game in hand. The ninth-place Jets sit three points behind, the same amount Winnipeg trails the Southeast Division-leading Capitals. “I think we’re playing the best hockey we’ve played all year,” said Callahan, who started the scoring just 34 seconds into the game and added his 14th of the season on a third-period power play that made it 4-0. “Now is the time to do that, with us battling for a playoff spot and hopefully heading into the playoffs.” It might have been a game that was always in the hands of the Rangers, now 8-2-1 in their past 11. Yet it was one the Devils, winners of two straight coming in — following a backbreaking 10-game winless streak — weren’t about to take lying down.