Inter Milan, bidding for a first Scudetto since winning the treble under Jose Mourinho in 2010, are now one point clear of AC Milan, with Roma six points further back in third.
Lazio cruised to a 3-0 victory over city rivals Roma on Friday, equalling their best ever derby victory in Serie A.
Serie A: Benefiting from the stalemate between AS Roma and Inter Milan, champions Juventus powered up to fourth with a 3-1 win over 10-man Sassuolo.
Napoli came from a goal down to beat Sampdoria 2-1 at the newly-named Stadio Diego Armando Maradona while Inter Milan beat Cagliari 3-1.
In Naples, players took to the pitch wearing a special Argentina-inspired jersey in tribute to Diego Maradona.
Gennaro Gattuso's side entered the field all wearing the number 10 jersey of Diego Maradona, who won Napoli's only Serie A titles in 1987 and 1990 as well as the 1989 UEFA Cup.
Roma legend Francesco Totti on Monday visited a teenage girl in hospital who emerged from a nine-month coma after hearing a recording of the former Italian football star's voice.
Cristiano Ronaldo headed in the equaliser in the 69th minute for Juventus to avoid handing new coach Andrea Pirlo a first defeat.
AS Roma's campaign got off to a sluggish start under the new ownership of US billionaire Dan Friedkin, with last year's fifth-place outfit settling for a point.
Arsenal, on its site, said Monday evening it had agreed to terminate Henrikh Mkhitaryan's contract by "mutual consent to allow him to join AS Roma as part of a final transfer".