Japan coach Alberto Zaccheroni believes Napoli could eat into Milan's Scudetto hopes, but Inter are still on course despite stumbling against Juventus.
It's tight at the top in Serie A with eight points separating the top four following the weekend's action.
Inter fell at Juventus, while Milan and Napoli maintained the charge following wins against Parma and Roma respectively.
And Zaccheroni has said the race is still wildly on.
"For Inter the championship is still open and I wouldn't exclude them even though Napoli and Milan are doing so well," he told Radio Anch'io lo Sport.
"Many undervalue Napoli's strengths, but I wouldn't.
"Napoli don't have the same squad as others, but they can take full advantage if Milan and Inter slip up."
Juventus are back on the crusade following their 1-0 triumph over Inter, but Zaccheroni, their former coach, feels it's not enough from the Bianconeri.
"Juventus were very compact against Inter last night. But the problem is to maintain this against the weaker sides," he said.