"I've had good looks the last couple of games. When I have looks, I try to take advantage of them," said Williams, who was 8 of 12 from the field, 5 of 6 from the free throw line and had eight rebounds.
It was his second consecutive solid game after three games in which he failed to score more than seven points.
"I've been working. Been at the gym at 8 o'clock every morning. Me and my father have been working on some things, and it's definitely paying off for me," said Williams, who averages 10.1 points a game.
Williams had 18 points and nine rebounds in Monday night's 116-92 win at Chicago.
"He's had two solid games in a row. We need Marvin to play like that. When he does, it takes pressure off everybody," said Atlanta coach Mike Woodsen.
"It makes it easy for everybody when he does that. I love it when he does that," said Johnson.
The 76ers, who have lost four in a row and seven of nine, were led by Lou Williams, the 76ers second round pick in 2005 out of suburban Atlanta High School South Gwinnett, who had 30 points. He hit his first 10 shots and finished 11 for 15 from the field and 7 of 10 on free throws before a crowd that included many friends and relatives.
"I'm sure my family, my friends enjoyed it," he said. "It's not individual victories when you lose. The points I scored don't really mean a lot because we lost."
Atlanta, which improved to 24-7 at home, led 87-68 after three quarters on a 3-point basket by Crawford just before the buzzer.
The Hawks' biggest lead was 20 twice -- at 94-74 on a 3-point play by Williams with 7:50 left and at 103-83 on a 3-point basket by Crawford with 3:28 left.
The closest Philadelphia got was 63-57 on a basket by Williams, with 10:30 left in the third period. The Hawks then went on a six-point run for a 69-59 lead and the 76ers never got closer than eight points the rest of the way.
"I like how Lou stepped up and was aggessive. The Hawks are one of the top teams in the Eastern Conference, so you almost have to play perfect in order to have a chance at beating them," said Philadelphia coach Eddie Jordan.
The Hawks led 61-51 at halftime with Williams scoring 12 points and Johnson 11. Williams had 17 points for the 76ers. He was 6 for 6 from the field and 4 for 4 at the line.
Atlanta's biggest lead of the opening half was 13 points, the last at 49-36 on a basket by Al Horford with 4:52 before intermission.