Champions Juventus took a huge step towards retaining the Serie A title by beating second-placed Napoli, with both sides reduced to 10 men.

Napoli goalkeeper Alex Meret was given a straight red card for tripping Cristiano Ronaldo and Miralem Pjanic curled in the resulting free-kick.

Emre Can headed a second, before Pjanic was dismissed for deliberate handball.

Jose Callejon pulled a goal back and Napoli's Lorenzo Insigne missed a late penalty.

The spot-kick was awarded by the VAR six minutes from time after Fabian Ruiz's cutback hit Alex Sandro on the arm, although the Juventus defender knew little about it.

Referee Gianluca Rocchi jogged over to have a look at the replay on the pitchside monitor and awarded the penalty, but Insigne rattled the post.

Relive Juve's victory over Napoli

Piotr Zielinski also hit the woodwork for the home side at 1-0 down and saw two further efforts saved by Poland international team-mate Wojciech Szczesny.

Juve have won the title for the last seven seasons and now hold a 16-point advantage with 12 games remaining.

Elsewhere, Fiorentina's game at Atalanta was paused in the 13th minute as the two sides and supporters paid tribute to former Viola captain Davide Astori who died on 4 March last year at the age of 31. The hosts won the game 3-1.

Meanwhile, veteran Sampdoria striker Fabio Quagliarella took his tally to 19 league goals for the season with a double at SPAL.