"I didn't shoot well, but at the same time I was able to do other things," Johnson said. "My teammates were making shots. I was just trying to crash the boards, get rebounds and just make plays."
Kevin Durant scored 28 points for the Thunder, who have lost 10 of 11. Oklahoma City fell to 1-13 on the road and 3-26 overall despite a combined 26 rebounds by Jeff Green and Chris Wilcox.
The Hawks have won three straight and six of seven. They improved to 11-2 at home.
Johnson's follow shot with 32 seconds left before halftime made it 44-43 and gave Atlanta the lead for good. But with the outcome still uncertain, Johnson showed how much he means to the Hawks in a 12-second span of the fourth quarter, pulling down a defensive rebound and feeding Josh Smith for a 3-pointer.
Smith's basket, which made it 88-81 with 2:32 remaining, prompted Oklahoma City to call a timeout. After the Hawks walked back onto the floor, Johnson learned he needed two assists for a triple-double.
"It's cool, but it's not the biggest thing on my list," he said. "Don't get me wrong. A triple-double is sweet. It's a great accomplishment because it lets you know you've been active on both ends of the court. I was just trying to be aggressive and make plays."
Johnson's other triple-double came on Feb. 1, 2006, when he had 15 points, 10 rebounds and 11 assists in Atlanta's 102-92 victory at Charlotte. Against Oklahoma City, he was 8-for-23 from the field and nearly 10 points under his season shooting percentage of 44.9.
"It's unbelievable," Williams said about Johnson, who leads Atlanta in scoring for the fourth straight year and last season played 82 games for the fifth time in his career. "We're in good shape right now. Obviously, this is the best team I've ever been on since I've been here."
Durant's 19-footer with 3:18 remaining cut the lead to 85-81, but the Thunder failed to score on their next three possessions and trailed by nine after Mike Bibby's 14-footer from the right baseline at the 1:37 mark.
"They hit a lot of big shots tonight and they got a lot of stops," Durant said. "That's why they're a playoff team. Teams make their run, but we can't allow that. We could have made more shots but we didn't. Joe Johnson made shots when he needed to, and with a triple-double, it shows what type of player he is."
Green tied a career high with 14 rebounds and finished with 18 points. Wilcox, in 24 minutes, had 19 points and a season-high 12 boards.
"It was Joe Johnson's game tonight," Wilcox said. "He had an answer for everything. He hit big shots all night, and that's why they brought him here."
Thunder C Joe Smith, starting for the first time this season, had eight points and five rebounds after Nick Collison missed the game with a broken left thumb. Collison got hurt in a loss to Cleveland on Saturday, but could return Friday at Detroit. ... Durant has scored at least 20 points in a career-best eight consecutive games. ... Atlanta improved to 17-4 when holding opponents under 100 points. ... Oklahoma City has lost six straight on the road since winning at Memphis on Nov. 29.