Though he can do anything on a basketball court, one of the plays LeBron James is most known for is the chase-down block.In the NBA Finals last year, LeBron came from behind to emphatically swat an Andre Iguodala layup attempt off the glass to preserve the tie score in what would eventually be the Cleveland Cavaliers' title-clinching victory.Other players may try to emulate LeBron's signature play, but none come close to matching King James when it comes to flying out of nowhere to deflect a shot.During Game 1 of this year's Eastern Conference Finals, James was driving for a layup when Boston Celtics star point guard Isaiah Thomas attempted the chase-down block. As you can see in the video below, it did not go well for Thomas:

Though IT had his headband knocked off his head when he was hit in the face by LeBron, he gets some much-deserved credit for preventing James from making the layup and sending him sprawling to the floor in the process.

LeBron knocked down both ensuing free throws, but the Celtics will trade two free throws for an easy layup anytime.

One of the keys to Thomas's game is that, even though he is only 5'9" tall, he's not afraid to go up against anyone in the NBA. Even against James, who is one of the strongest and most athletic players ever to play in the league, IT is willing to put his body on the line for his team.

After the 117-104 loss, Thomas told ESPN.com that he and his teammates need to be even more physical with the Cavaliers on the defensive end of the floor if they're going to have any shot of advancing to the NBA Finals:

"They were the better team tonight. The hit us first. They were more physical," Thomas said. "We can't let that happen again."

The Celtics need to especially focus on keeping James away from the rim. On Wednesday, he scored a game-high 38 points while only making one three-pointer and nine free throws. That means 26 of his 38 points came from inside the arc, and many of those came at the rim.

As the series goes on, the Celtics will need someone other than Thomas to challenge more of James's shots if they're going to have any chance of extending the series to even five games.

Because, after sweeping the Indiana Pacers and Toronto Raptors earlier this postseason, the Cavs showed no signs of slowing down during Game 1 in Boston.