"We just wanted to keep everybody on the same track so we could stay focused with the playoffs coming up," Horford said. "I think it went well."
Rodney Stuckey missed two jump shots in the final 1:14 but still led the Pistons with 22 points in a reserve role. Chris Wilcox added 18, and Greg Monroe scored 17 for Detroit, which has lost seven straight on the road and is 7-28 away from home.
"That's a tough way to lose," Monroe said. "They're a good team and they made the plays down the stretch to win the game."
Since losing by seven at home to Oklahoma City on March 4, the Hawks had been beaten by an average of 16.2 points in their last six defeats.
The slide prompted Horford to bring his teammates together after Saturday's practice.
"Energy, effort. When we do that, we are a pretty good ballclub," Smith said. "We have to be consistent. We can't be like a roller-coaster."
Atlanta took its biggest lead at 14 when Kirk Hinrich's reverse layup made it 72-58 with 5:08 left in the third. The Pistons came within two in the first minute of the fourth quarter on a 3-pointer by Charlie Villanueva that made it 79-77.
By the 7:27 mark of the fourth, Horford, one of six Hawks to score in double figures, banked in a jumper and was given a hard foul by Villanueva. Horford completed the three-point play to give Atlanta an 11-point lead.
"I'm always trying to find somebody on the break," Horford said after pulling down 10 rebounds for his 32nd double-double. "They happened to pick me up, so I kept attacking. I shot it when he hit me, just trying to make a play."
Smith banked in a left-handed runner with 52.1 seconds over Austin Daye to beat the shot-clock buzzer and give the Hawks a 100-95 lead.
Johnson matched Stuckey with a game-high eight assists, and reserve center Zaza Pachulia added 13 points -- including 9 of 10 from the line. Hinrich scored 15 points and made three 3-pointers.
Atlanta bounced back from a 106-85 home loss to Miami on Friday night.
"I thought our guys willed themselves to tonight's win," Hawks coach Larry Drew said. "I thought Al was magnificent. I thought Josh Smith was really good. I thought Zaza came in off the bench and gave us some really good minutes."
Detroit, which was coming off consecutive wins for the first time since Feb. 4-5, has lost 12 of 17. Despite another setback, Pistons coach John Kuester saw some encouraging signs.
"When we play with this kind of energy, which we have done as of late, it's evident that guys are trying to do the right things," Kuester said.
Nine of the Hawks' last 10 games have been at home. They are 4-5 in that span. ... Detroit has used 19 starting lineups. ... Starting Pistons guards Tracy McGrady and Richard Hamilton combined to score 10 points on 4 for 17 shooting. ... The Pistons fell to 4-27 when trailing after the first quarter and 7-36 when trailing after the third. ... Reserve point guards Jeff Teague of Atlanta and Will Bynum of Detroit didn't play due to coaches' decisions. Teague was averaging 13.2 minutes, Bynum 18.