Cristiano Ronaldo rescued Juventus at the death as his penalty delivered a barely-deserved 2-1 win over Genoa at Allianz Stadium.
Juve needed to respond to Inter Milan's victory at Brescia 24 hours earlier to return to top spot, and Leonardo Bonucci's 36th-minute header sent them down the right path.
Christian Kouame's miskick fooled Juve goalkeeper Gianluigi Buffon as Genoa levelled four minutes later, yet the dismissal of Francesco Cassata after half-time gave the hosts the upper hand once more.
They could not make their personnel advantage count and lost it when substitute Adrien Rabiot saw red in the 86th minute.
Ronaldo was offside when he put the ball in the net deep into stoppage time - yet he was subsequently caught by Antonio Sanabria in the box and made no mistake with his penalty, sparing Juve blushes.
Atalanta make point, Smalling strikes in Roma rout
Atalanta kept top-three rivals Napoli at arm's length by forcing a 2-2 draw at the Stadio San Paolo.
Nikola Maksimovic's 16th-minute headed goal from a Jose Callejon cross briefly brought Napoli into a share of third place with their in-form guests, but Remo Freuler levelled shortly before half-time.
Arkadiusz Milik, who had hit a post midway through the first half, restored Napoli's lead by rolling home a Fabian Ruiz through ball in the 72nd minute. Josip Ilicic beat the offside trap to equalise four minutes from time, however,
and the Slovenian was then denied a winner in stoppage time.
Both Rome clubs trounced their respective opponents 4-0, with Roma climbing to fourth and Lazio to fifth.
At Udinese, Nicolo Zaniolo exploited a defensive mistake to give Roma the lead. The Giallorossi survived losing Federico Fazio to a harsh red card to pull clear through Chris Smalling, Justin Kluivert and an Aleksandar Kolarov penalty.
Lazio thrashed Torino with a brace from Ciro Immobile arriving after Francesco Acerbi scored from 35 yards and before Andrea Belotti contributed a late own goal. Immobile's second was a penalty, with Nicolas Nkoulou dismissed for conceding it.
Joao Pedro helped Cagliari recover to beat Bologna 3-2 in Sardinia.
Federico Santander's spot-kick put Bologna in front before Pedro's double and Giovanni Simeone's chipped finish turned the game on its head, with home keeper Robin Olsen putting through his own net in second-half stoppage time.
Gaetano Castrovilli scored one and set up Nikola Milenkovic's winner as Fiorentina responded well to Jeremie Boga's fine opener for Sassuolo to triumph 2-1.
Elsewhere, 10-man Lecce were denied all three points from their trip to Sampdoria as Gaston Ramirez's headed goal right at the death forced a 1-1 draw. Gianluca Lapadula had the southerners ahead eight minutes in but the dismissal
of Panagiotis Tachtsidis saw Lecce steadily lose control of proceedings.