So now we see how tough the Knicks really are, how resilient, how bold. Now they are forced to answer for their season, defend it, fight to preserve it. That mild discomfort they felt in the opening round, against Boston? In truth, that was nothing but a tug from history, a minor nudge. The Knicks won the first three games against the Celtics, never trailed after the first few minutes in the only moderately critical game of that series, Game 6, and wound up being too far ahead to be taken down even by a 20-0 spurt. At no time were they in serious jeopardy. At no time was their season in serious peril. It is now. “I thought they played harder than our team tonight,” Knicks coach Mike Woodson said when the Pacers closed the books on this decisive 102-95 victory. “Loose balls, things of that nature ... they did all the little things. We didn’t play until we got down and there was desperation, and you’ve got to play that way from the start.” Said Carmelo Anthony: “They outplayed us here today. They outworked us.” Yes: It’s thoroughly dispiriting that in a precious playoff game at home the Knicks’ coach and star would all but concede the Knicks mailed it in, postage due. And, yes: It is only one game. If the Knicks can get even tomorrow night, they have about a month and a half before Game 3 in Indianapolis (actually, only four days), and there are more than a few of them — starting with Anthony — who can use a couple of low-impact days. They didn’t lose the series yesterday, as completely as the Pacers dominated. But they awaken today to a brave new world completely unfamiliar to them so far this season. For every miniature crisis the Knicks have absorbed and endured — notably the 1-4 West Coast trip that nearly derailed the season in March — they have had an immediate answer.