The legal battle between the entities in control of Michael Jackson's estate and the two men who claim they were sexually abused by the King of Pop is heating up ... and there's a lot of finger-pointing.

A Los Angeles judge sided with accusers Wade Robson and James Safechuck's move to stop Michael Jackson’s team from adding new arguments to their defense.

The lawyers for MJ's side were trying to amend their answers to the men's complaints so they could argue others are responsible for the alleged abuse of Wade and James ... and not MJ's companies.

In the filing, the lawyers adamantly dispute that Michael ever abused a child ... and point out Wade and James, and their parents, were among MJ's strongest supporters until well after his death.

The companies argued that, even if a jury believes the allegations of abuse, they should be allowed to make the argument that others who were not sued should also potentially be on the hook for damages ... including third parties who they say encouraged and facilitated Wade and James' friendships with the late singer.

Wade and James argued the defendants waited too long to add the argument ... and asked for the request to amend the suit be denied.  The court ended up denying the companies' motion to amend the complaint at this stage of the case ... but left the door open for them to file a renewed motion for leave to amend if appropriate down the line.

As TMZ first reported, Wade and James are seeking over $400 million in damages from MJ's companies.

Wade claims MJ abused him when he hung out with him after meeting him when he was 7 ... and James says he met the singer while working on a Pepsi commercial in 1986 and claims he was abused in the years after the introduction.