Juventus left it late to beat AC Milan 2-0, while Udinese and Cagliari are well-placed among the frontrunners following Sunday's action.
Palermo picked up maximum points from their latest outing, while struggling Parma secured a welcome win and Cesena are finally off the mark.
Juventus' clash with defending Serie A champions AC Milan looked destined to end in a goalless draw, before a burst of activity in the final few minutes.
Claudio Marchisio broke the deadlock for Juve on 87 minutes and Milan were then reduced to ten men when Kevin-Prince Boateng was sent off for a second bookable offence.
There was still time for Marchisio to score a second and lift Juve to the top of the Serie A table.
Udinese had temporarily moved to the Serie A summit with a 2-0 victory over Bologna.
Mehdi Benatia opened the scoring for Francesco Guidolin's side on 29 minutes as they stretched their unbeaten start to five games.
Club captain Antonio Di Natale wrapped up the points from the penalty spot with 18 minutes left on the clock.
Cagliari were the weekend's big movers, with a 2-0 victory over Lecce lifting them into the top four.
Cardoso Thiago Ribeiro (10) and Davide Biondini (40) got the goals for the visitors.
Parma clambered out of the bottom three with a 3-1 win over Bologna.
Sebastian Giovinco was the star of the show for the hosts as he netted twice (29 & 42) before half-time.
Stefano Morrone (50) added a third after the interval to end the game as a contest, with Rodrigo Palacio's late consolation counting for little.
Lazio came from behind to see off Fiorentina 2-1.
Alessio Cerci opened the scoring after eight minutes for the Viola, but Hernanes restored parity shortly before the half-hour mark.
It appeared as though the spoils would be shared as time ticked down, but Miroslav Klose grabbed a winner for the visitors seven minutes from time.
Palermo edged out Siena 2-0, with Giulio Migliaccio's 19th minute effort and a stoppage-time penalty from Abel Hernandez proving to be the difference between the two sides.
They were forced to play over half an hour with 10 men after Federico Balzaretti saw red, but they were able to grind out a hard-fought win.
Novara were held by Catania in a six-goal thriller at Silvio Piola.
Nicola Legrottaglie (14) and Franceso Lodi (56) had the visitors in front on two occasions, but they were pegged back by Marco Rigoni (pen 49) and Takayuki Morimoto (65).
Novara took the lead five minutes from time when Jeda pounced, but Catania rescued a point in the dying moments when Alejandro Dario Gomez fired home.
Cesena picked up their first point of the season in a 0-0 draw with Chievo.