James pulled off the jaw dropping jam with about seven minutes remaining in the first quarter of Thursday's 113-105 setback at the Moda Center in Portland.
The Cavaliers trailed 14-13 when James decided to take on Blazers forward Al-Farouq Aminu beyond the 3-point line. He blazed past the defender and sprinted toward the rim.
The four-time NBA MVP then launched himself into the air above the paint and held the ball very high in his right hand, before bring it down with unparalleled might right in the face of Nurkic.
James had 22 points and six rebounds at halftime, but the Cavaliers trailed 59-54. He finished the night with a game-high 35 points, 14 rebounds and six assists.
Cleveland battles the Chicago Bulls at 8 p.m. Saturday at the United Center in Chicago. C.J. McCollum had 29 points to lead the Blazers.
"We sustained effort tonight. They got up to double digits on us in the third quarter where they made a run, but we sustained our energy," James told reporters after the loss. "We sustained our effort and we left everything on the floor."