LeBron James denies Boston’s Aron Baynes at the rim in the first half Saturday in Cleveland. (Gregory Shamus/Getty Images)

CLEVELAND — Al Horford is hesitating and LeBron James is pouncing. And this can’t be good for anyone wearing green.

In Game 3 of the Eastern Conference finals Saturday night, Horford, the center of the Boston Celtics’ offensive universe, decides to shoot a three-pointer. Actually, no. Horford has to think again because he’s surprised by the 6-foot-8, 250-pound obstacle flying in his direction.

Horford has already elevated to take the shot but instead of following through, he tries to escape the pressure by looking toward Celtics rookie Jayson Tatum, who’s raising his hand and scooting deeper in the left corner.

Leaving your feet to make an ill-advised, last-second pass is a basketball no-no. But attempting to do so against a motivated James equates to an unforgivable basketball sin. As the play developed, James snuffed out the pass before Horford could get it cleanly out of his right hand. Boston turnover.

As far as pivotal plays in the Cavaliers’ 116-86 victory over the Celtics, this one likely won’t be spliced into the highlight reel. Cleveland made 17 of 34 three-pointers while James scored 27 points and sprinkled in marvelous passes while compiling 12 assists. Those moments corrected the Cavaliers’ course in this matchup.

And yet, James making the effort to rush and recover on Horford, forcing a steal then a subsequent foul early in the second quarter, should rank above anything else he did in loosening Boston’s stranglehold on the series.

The Cavaliers played staunch defense. Center Tristan Thompson handled most of the Horford assignment and limited him to four shot attempts. Overall, Boston suffered within its sets, which resulted in too many long twos and 16 missed threes. But James showing up as a defensive partner, and not a pedestrian, helped Cleveland breeze to the Game 3 win.

“Just tried to put myself in position to help our team. I think tonight as a group, even when things broke down, we just covered for one another. We made them make extra passes. We made them make extra dribbles,” James said. “We were flying around, and I just happened to be one of the guys on the floor that wanted to fly around as well.”

While James has received plenty of adoration for carrying the Cavs in the playoffs, he has not deserved praise for his defense. During this postseason run, five other teammates rank higher than James in defensive rating (109.0 points per 100 possessions).

The rating shouldn’t be fit for a king. On Saturday, James finally decided to defend, or as he put it, “fly around.”

In the opening frame, James met 6-foot-10 center Aron Baynes at the rim and in the second quarter; he sent back Semi Ojeleye’s layup attempt, as well. As James played rim protector, the Cavaliers engulfed the perimeter.

The Celtics’ shooters in Tatum, Marcus Morris, Jaylen Brown and Marcus Smart missed seven midrange jumpers — the type of regrettable attempts that lead to 39.2 percent shooting.

“That’s what every single basketball team across the world wants,” Cavs forward Larry Nance Jr. said. “I just thought we did a really good job of not letting them beat us off the dribble but also shrinking off the guys on each wing to give the illusion that we’re there but kind of confusing the ballhandler.”

James perfected the art of bluffing on the play against Horford, who thought he had the shot until the surging black No. 23 jersey appeared.

Long after the game, James answered questions about his performance and shared his longest response when asked to recall three of his special passes that turned into assists — a pair of lefty deliveries and a wraparound beauty.

“I think my passing is up there with every other aspect of my game,” James said.

When James plays defense like he did Saturday, his work on that end belongs up there, too.

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