Johnson scored 23 points in his best game since his return from surgery on his right elbow to lead the Hawks past Antawn Jamison and the Cavaliers, 98-84 on Wednesday night.
Johnson missed nine games after the surgery and then struggled to regain his form in his first three games back in action. He returned to the form of the All-Star who has averaged more than 20 points in each of his first five seasons in Atlanta.
"Joe came back without any practices, and he finally found the stroke," Atlanta's Josh Smith said. "He played lights out tonight."
Johnson reached 20 points for the first time since scoring 21 in a win over Washington on Nov. 25.
The Hawks, coming off an emotional home win over Orlando on Monday night, led by only three points at halftime.
"The tendency is to have a mental letdown," Hawks coach Larry Drew said
Led by Johnson, the Hawks pushed the lead to 13 points with a strong start in the second half.
Jamison had 23 points but the Hawks were stronger with their typically balanced attack in their eighth straight home victory.
Johnson hit consecutive 3-pointers midway through the fourth quarter to push Atlanta's lead to 13 points at 91-78.
"I could be 6-9 and you're not going to stop those shots," Gibson said. "Those were tough shots. He just got it going and got the separation they needed. You can't guard guys like that individually. It's more of a team effort."
Cavaliers coach Byron Scott said it was no surprise Johnson had the biggest shots of the game.
"That's what great players do," Scott said. "Those guys are difference-makers. Joe's not an All-Star and one of the better players in this league for nothing. When they needed some big shots, he seemed to make the timely ones."
Johnson has played four games since he missed nine games recovering from surgery.
"I got into a little rhythm in the fourth quarter," Johnson said. "I hadn't been feeling that rhythm."
Johnson was initially expected to be out four to six weeks, but he returned less than three weeks after the procedure to remove loose cartilage in his shooting elbow.
"I still can't extend all the way," Johnson said, referring to his right arm. "But I can come out with a free mind."
Hawks coach Larry Drew said he was encouraged to see Johnson return to his familiar lead scoring role.
"I was very happy," Drew said. "I could see that he was getting into a rhythm. Joe is a rhythm guy. You could just see it."
The Hawks led only 49-46 at halftime before pulling away with a 20-10 run to start the third quarter. The surge followed Drew's sharp reminders to play defense.
"At halftime I had to let them know my way," Drew said. "They came out in the third quarter and responded very well."
With a game-high 11 assists, Williams had his fourth straight double-double in points and assists. He said he is playing with a sore groin.
Cleveland's last road win came was Nov. 9 at New Jersey. ... Hawks G Jamal Crawford missed his fifth straight game because of back spasms. He said he plans to join the Hawks on their trip to New Orleans and Milwaukee, but he still has obvious stiffness in his back. ... Cavaliers F Leon Powe (finger abrasion) was in uniform but did not play.