Charlotte scored the game's final six points, four of them coming from Walker. He took a pass from Gerald Henderson and hit one from beyond the arc after C.J. Miles had scored on a layup to lift the Cavaliers into an 84-84 tie.
The Cavaliers went scoreless for the final 2:14 of the game.
Charlotte won its home opener, leaving both teams with a 1-1 record.
Walker scored 23 points to lead the Bobcats and Michael Kidd-Gilchrist had 15.
Cleveland was paced by 22 points off the bench from Miles. Tristan Thompson contributed 21 points and 11 rebounds.
The clutch 3-pointer from Walker was one of just three made by Charlotte in 12 tries.