Simone Padoin scored the sole goal of the match in the 72nd minute to help the hosts score their 31st win of the season -- a record in the Italian top flight, Xinhua reported.
The Turin club, who had sealed their 30th Scudetto without kicking a ball on Sunday when Roma lost 4-1 against Catania, have now already garnered 96 points.
Juve almost went ahead in the 26th minute when Atalanta goalkeeper Andrea Consigli was forced to put on a superb save to deny Daniel Osvaldo's header from Stephan Lichtsteiner's cross.
The hosts became more dangerous after their top scorer Carlos Tevez came on in the 65th minute as a substitute, and Consigli was twice called into action to clear close-range attempts from Fabio Quagliarella and Paul Pogba.
The deadlock was finally broken when Pogba set up Padoin and the former Atalanta player hit a right-footed shot from the centre of the area past Consigli.
In the other kick-off of the day, Lazio drew 3-3 with Verona at home thanks to midfielder Stefano Mauri's ast-gasp equaliser.
Verona, who were behind twice in the game, took the lead for the first time when substitute Romulo gave them a 3-2 lead with seven minutes remaining.
But Mauri tapped in his own missed penalty to salvage one point for Lazio, who had Senad Lulic sent off for a straight red minutes before.
Keita put Lazio ahead on the half-hour mark but Hellas striker Marquinho equalised seven minutes later.
Lulic put the home side back in front after one hour of play only for Juan Manuel Iturbe to make it 2-2 nine minutes later.
The outcome at the Stadio Olimpico has left both sides in the top half of the standings, level on 53 points.