Photo: Charles Krupa (AP)

An all-timer of a first quarter from LeBron James, in which he scored 21 of his team’s 27 points, and a 42-point triple-double for the entire game all went to waste in Game 2 of the Eastern Conference Finals, as the Boston Celtics took down the Cleveland LeBrons, 107-94.

The potentially most impactful (and scary) play of the game came late in the second quarter, when LeBron had to go to the locker room for what the Cavs called a “neck strain” after a collision under the basket with Jayson Tatum. Whether or not the collision actually did any lasting damage to LeBron (he was only out for a couple of minutes), it coincided with the moment Boston’s comeback began. Cleveland led 46-36 when it happened, then proceeded to get outscored 71-48 for the rest of the night.

It’s a bit unfair to reduce the still very talented Celtics to a bunch of scrappy role players fighting a giant while their stars are sidelined, but it’s still true that—LeBron excluded—the ’Tics played smarter, more disciplined, and more motivated basketball than any of the Cavs, and that was the difference. Boston only made six turnovers all game, shot 17-of-20 on free throws, and had six different guys in double figures. Jaylen Brown was the team leader with 23 points, but everyone in green and white had some sort of contribution to make.

They tied the bow on this game on a possession with six minutes to go, when the Celtics got two offensive rebounds and stretched their lead to double digits with a flying putback from Marcus Smart, who was plus-21 for the night with 11 points and nine assists in 31 minutes off the bench.

None of the Cavs’ bench guys were even attempting plays like this. Cleveland’s secondary players, in sum, were nothing but a couple of Kyle Korver threes. J.R. Smith couldn’t make a shot on seven attempts but contributed a blatantly dirty push to the back on a mid-air Al Horford late in the fourth. George Hill scored three points in 33 minutes. Jeff Green had six in 28. Kevin Love is at least doing his job, but after the Cavs played a fantastic series against the Raptors, they’re back to LeBron stuck on an island with a rising tide around him. Only a fool would count him out now, and LeBron previously came back from this deficit in 2016 against the greatest regular season team ever. But after tonight, Cleveland’s hand has got to be hovering over that panic button.