The injury-prone Holland international has not been prolific since moving to the capital three years ago, but he picked a great time to score his seventh league goal for Luciano Spalletti's Giallorossi, who have held the bragging rights at the Stadio Olimpico since before Strootman arrived.

However, after chipping Lazio goalkeeper Federico Marchetti for the Derby della Capitale opener, his disrespectful actions towards the designated home team sparked a brawl and got substitute Danilo Cataldi sent off for reacting badly. Their nerves shot, Lazio conceded a second goal to Radja Nainggolan.

Earlier in the day, the Giallorossi had been set a target of catching fellow title hopefuls AC Milan, who left it late to beat lowly Crotone at San Siro.

They were indebted to Gianluca Lapadula for their slender 2-1 win as the Italy international scored four minutes from time to add to Mario Pasalic's equaliser.

Diego Falcinelli had given the visitors a shock early lead and the southern strugglers looked to have taken a point when M'Baye Niang's penalty was saved.

Sassuolo had been in free fall before getting back to winning ways with a 3-0 home victory against Empoli.

Two first-half penalties from Lorenzo Pellegrini and Federico Ricci set the Neroverdi on their way and Antonino Ragusa sealed the deal after the break.

Torino's rapid ascent of the table was checked by Sampdoria, who ended their three-game winning run with a 2-0 triumph at the Marassi. Edgar Barreto and substitute Patrik Schick grabbed the goals that ensured Samp made it five games without defeat.

Elsewhere, Gianluca Caprari's late leveller earned relegation-threatened Pescara their share of the spoils from a 1-1 draw with Cagliari, who had Davide Di Gennaro dismissed shortly after Marco Borriello got on the scoresheet on the east coast.