Jennifer Hudson played super dirty by sneaking into court to get an order of protection against baby daddy David Otunga to get a leg up in their custody dispute ... so claims Otunga's lawyer.
Attorney Tracy Rizzo just filed legal docs asking the judge to throw out the order of protection a judge granted Thursday, forcing Otunga out of the family home and requiring him to stay clear of Jennifer and their 8-year-old son, David Jr.
Rizzo says she and David were blindsided by the order of protection and Hudson's lawyer never gave them any notice of the hearing.