Napoli took full advantage of Inter Milan's first defeat of the Serie A season to take over at the top.
Udinese called time on Inter's 16-match unbeaten run with Kevin Lasagna, Rodrigo De Paul and Antonin Barak scoring the goals in a 3-1 victory at San Siro.
Later, sitting a point behind the Nerazzurri before they tackled Torino, Maurizio Sarri's Napoli scented blood and Kalidou Koulibaly, Piotr Zielinski and Marek Hamsik made it 3-0 before half-time.
It was a 115th goal for Slovakian midfielder Hamsik, who thus matched Diego Maradona's long-standing record scoring haul for the Naples club.
In addition to re-establishing Napoli as title challengers to be feared, the 3-1 triumph in Turin ended a worrying sequence of toothless performances.
The southerners drew blanks against Juventus and Fiorentina in their last two league games and lost 2-1 to Champions League strugglers Feyenoord last week.
But here their incisive play was back on display, with Allan, Jorginho and Dries Mertens providing assists for the goals from different parts of the pitch.
Torino striker Andrea Belotti also enjoyed a timely fillip as he recorded his first league goal since September, rattling in Adem Ljajic's second-half assist.
There had been no such joy for Inter, though. Just days after their embarrassing 120-minute toil against third-tier Pordenone in the Coppa Italia, they were overrun by mid-table Udinese.
Lasagna's opener was quickly cancelled out by Inter captain Mauro Icardi but a second-half collapse saw De Paul convert a penalty and Barak confirm Udinese's third straight win with his late effort.
Sven Ulreich saved Chadrac Akolo's 95th-minute penalty as Bayern Munich ground out a hard-fought 1-0 win at Stuttgart.
Ulreich got down to hold Akolo's weak spot-kick, awarded by the Video Assistant Referee for Niklas Sule's foul on Santiago Ascacibar. It proved the final act of the match.
Second-half substitute Thomas Muller got Bayern's winner against stubborn opponents, firing a snapshot inside the near post in the 79th minute after being picked out by Kingsley Coman.
Defeat was harsh on the hosts, who slipped to a fourth straight loss without scoring despite a disciplined display which frustrated the visitors for long periods.
The victory, though, lifted Bayern 11 points clear at the top of the Bundesliga table, with second-placed Schalke needing a late comeback to snatch a point in a 2-2 draw at top-four rivals Eintracht Frankfurt.
The Basque derby failed to catch fire as Athletic Bilbao and Real Sociedad played out a goalless draw at San Mames.
With the sides separated by only two points in midtable in LaLiga, it was perhaps not surprising the match ended in stalemate, although visitors Sociedad enjoyed significantly more possession.
That did not translate into goalmouth action. Of the 16 efforts on goal during the game, only two were on target, one for each side.