Along with point guard Jeff Teague, who contributed 19 points and seven assists, the Hawks were too much for the struggling Jazz.
Utah led only once, 5-4 early in the first quarter.
"It thought it was a gutsy win," said Atlanta coach Larry Drew. "They were short-handed ... but this team is very tough to play in their building. I told our guys we had to control the tempo from start to finish. We had to try and keep the crowd out of it as much as we could."
Atlanta built an 80-60 lead late in the third quarter and fought off two rallies by the Jazz, who trailed 82-71 with 10 minutes left and 90-82 with five minutes remaining.
"I recall two scenarios when they made a pretty good run and the crowd got involved," Drew said "But we were able to defuse both those situations. We went to some zone, which I thought took them out of their rhythm a little bit."
Asked about Horford's dazzling performance, Drew said, "Yeah, he was big. We were running plays through him and, when his shot wasn't there, he was passing the ball. He got everything within our offense, and guys were doing a good job finding him. ... He is really playing at a high level right now."
The Hawks won for the third straight time on a six-game road trip that also takes them to Phoenix, L.A. and Denver.
"It's great better than we could expect," Horford said. "Coming into a place like this and getting a win against a good team like Utah, it's great. I'm proud of my teammates."
In the three road wins in the last five nights over Detroit, Milwaukee and Utah, Horford averages 26.6 points, 16 rebounds and three blocked shots.
"I'm in a good rhythm," he said. "Most importantly, we're winning and playing well as a team. Tonight was a big win for us."
Said Smith: "Al has been on a monstrous streak. [But] we've all been playing well collectively and having fun."
Against the Jazz, Smith said, "We just kept digging and playing hard. ... It is definitely difficult to play in this building. We had to match their physicality. They are such a physical team, especially in the paint."