The high-flying hammer came in the first quarter of the Pacers' Game 1 victory in the first round of the Eastern Conference playoffs.
Indiana led 28-10 before gaining a possession off of a series of missed LeBron James shots and sprinting out in transition. Cory Joseph dribbled up the court, before feeding Victor Oladipo at the top of the 3-point line. Oladipo then fired a pass to Stephenson, who was trailing on the play.
Stephenson decided to dash into the paint. He stood shoulder-to-shoulder with James, before rising up right in Jeff Green's face. Stephenson then used his right hand to stuff in the slam, giving the Pacers a 20-point lead.
He was also fouled on the play, but he missed the free throw. Stephenson posted five points in the first quarter. He finished the game with 12 points and five rebounds.
Stephenson was his typical amusing self after the dunk. He went up to the field goal and intentionally hit his head on the padding. The Pacers guard also continued his back-and-forth antics with James. After one play, James mimicked the head-butt by doing one himself. The two also engaged in a stare down.
Stephenson also added some extra flair to his defense on James and was called for a technical foul late in the third quarter for hitting him in the face with his hand.
Oladipo led the Pacers with 32 points, six rebounds and four assists.
James posted 24 points, 12 assists and 10 rebounds in the loss.
"He don't back down from nobody and I definitely don't as well," James told reporters, when asked about Stephenson. "It's going to be a good series."
Lance was T'd up after hitting LeBron in the head. pic.twitter.com/UWCqizgrkz— ESPN (@espn) April 15, 2018
Game 2 of the first round series tips off at 7 p.m. Wednesday in Cleveland.
"They are a great team," Stephenson told reporters. "We just have to stay under control, don't let this get to our head and take the next game as our first game."