One of the most fascinating concepts in sports is the spectacular collapse.

A team is way up (Dodgers over Giants, 1951; Yankees with a 3-0 ALCS lead over the Red Sox in 2004) , a sure thing, no problem at all, a fat lead … and then a break in momentum, a turning point, panic suddenly setting in … and that easy victory turning into something else ugly. Maybe memorable. Probably scarring.

That would pretty much cover what happened to Liverpool in a dramatic and unexpected English Premier League match tonight.

To set the stage:

Liverpool, behind only Manchester City, via tiebreaker, at the top of the Premier League, with 80 points, was expected to handle Palace.

Granted, Palace has improved since Tony Pulis took over after a disastrous start, but the Liverpuddlians are playing for their first league title since 1990. They have to get the job done here, right?

And it should happen, because Liverpool has been an irresistible force this year.

It was 1-0 at halftime, and then 3-0 Liverpool 15 minutes into the second half as Daniel Sturridge and Luis Suarez, their dynamic duty, each scored.

But …

Palace scored a sloppy goal, and it was 3-1 with 11 minutes left. (Someone cue the “dum-de-dum-dum” music), and those who were there, in Palace’s decrepit but noisy old stadium, said a shiver of fear ran though Liverpool supporters.

What undoubtedly was the day’s most watched sports event turned into a Liveerpool implosion.

The team coached by Brendan Rodgers was still coming forward relentlessly, looking for a big victory to reduce Manchester City’s tiebreaker advantage (via goal differential).

But when it got to 3-1, Liverpool should have bunkered in — not that they really know how to do that at the moment — and secured the three points.

City has a game Wednesday and, who knows, maybe Aston Villa can get a result.

Instead, Liverpool attempted to keep pushing and Palace got two counter-attack goals from Dwight Gayle in the final 10 minutes to forge a crushing draw on the Pool Guys, from 3-0 up to tied in 11 minutes.

Now Manchester City need only win and draw in their final two to take the title that looked like Liverpool’s a few hears ago.

Their coach ceded the title to City, though the comments had an element of psychological warfare to them — trying to shift the crushing pressure to City.

But the news out of this remains … the huge lead. The collapse. The draw or defeat.

Nothing crushes a franchise quite like that. All the good things Liverpool did this season … will not be remembered as well as that 11-minute span when they gacked up the Premier League title.

Or that’s how it looks, anyway.