Lazio's Senad Lulic was facing accusations of racism on Sunday for likening Roma's German player Antonio Rudiger, who is black, to a street seller hawking "socks and belts".

Goals by Kevin Strootman and Radja Nainggolan in the second half of a fiery derby at the Stadio Olimpico kept the local bragging rights with Roma for the fourth year in succession.

Lazio dropped to four points behind their city rivals after a match that saw six yellow cards and substitute Danilo Cataldi sent off for the hosts while he stood on the touchlines after an altercation with Strootman.

Lulic then added to the tension by comparing Rudiger to a street seller, claiming the Germany international defender had been provoking Lazio in public in the lead-up to the game.

In comments to Mediaset Premium, and widely reported in the Italian media, Lulic said: "He's been speaking too much even before this game. Two years ago, he was selling socks and belts in Stuttgart and now he thinks he's a phenomenon.

"But it's not his fault, it's the people who surround him that make him into someone who doesn't know how to behave properly."

Rudiger has a German father and a mother who hails from Sierra Leone. He joined Roma last year after a three-year spell with VfB Stuttgart.

The 23-year-old has played for Germany through the age groups starting at under-18 level, but missed last summer's Euro 2016 due to a torn cruciate ligament injury.