While Antonio Conte's reigning champions were being held to a 1-1 draw in Parma, a controversial finish from Sergio Floccari and Davide Brivio's own-goal saw Lazio take full advantage in their pursuit of top spot.
Floccari's opener had a suspicion of handball in the build-up and so Atalanta defender Carlos Carmona let his frustration boil over to pick up two quick yellow cards as time ticked away in Rome.
Lazio can draw level with Juve next weekend if they claim all three points at Palermo, should the Bianconeri lose at home to Udinese.
The shortest man on the pitch, Maxi Moralez, rose highest to meet a ball forward in the eighth minute, his header beating Federico Marchetti only for the goal to be ruled out for offside.
Luca Cigarini then tried the direct approach with a solid shot at Marchetti's goal but his accuracy was sorely lacking.
Atalanta were on top in the capital and Giacomo Bonaventura soon squeezed a low ball into the box, but Moralez could not beat Marchetti from close range at the second time of asking.
Brivio stole down the left wing to steer a pinpoint cross into the box, Giuseppe Biava rising well to clear, and the Atalanta midfielder should have done better with a half-volley from the resulting corner.
Lazio were being restricted to long shots and Hernanes' speculative effort did nothing to worry Andrea Consigli.
And just two minutes before the break, Atalanta should have claimed the goal their dominance deserved, but Guglielmo Stendardo could not convert Bonaventura's defence-splitting pass.
The Biancocelesti were much brighter as play resumed, with Miroslav Klose and Floccari dragging the Atalanta defence into disarray, but Stefano Mauri could not capitalise.
The German striker soon saw a snapshot deflected out for a corner and Consigli did well to punch a Hernanes free-kick clear as Lazio poured forward.
German Denis scrambled Lorik Cana's ball off the line with Consigli stranded, but the hosts had done enough to unsettle their opponents.
With 67 minutes on the clock, Floccari shrugged off accusations of having controlled the ball with his arm to twist his body and steer it home.
Atalanta then wasted up to three valuable minutes by appealing against the goal, with Carmona booked for his protests, but there could be no doubt over the own-goal.
In the 77th minute, Mauri drifted a high ball into the box and Brivio haplessly nudged it beyond Consigli to settle the game in Lazio's favour.
Atalanta had run out of steam and there was to be no comeback when the irate Carmona received his second yellow card, and his marching orders, seven minutes from time.