West Ham defender Anton Ferdinand believes "nasty" Mathieu Flamini has made the difference at Arsenal this season.
The Hammers defender said after his side's 1-0 defeat against the Gunners on Saturday: "Arsenal look more clinical to me than last year.
"They got that vital first goal from Robin van Persie and they were very good at keeping that advantage.
"Cesc Fabregas is already looking great this season but Mathieu Flamini has given them that nasty look that perhaps they lacked. Every top team needs one of those battling type players in midfield who can really tackle."