Firebrand attorney Alan Dershowitz has filed his own lawsuit against accuser Virginia Roberts Giuffre — claiming she’s a money-grubbing opportunist out for a payday.

“Dershowitz never met Giuffre and never had sex with her,” lawyers for the Harvard Law professor write in new court papers, filed Thursday in Manhattan federal court.

The counter-suit, which is a response to Giuffre’s own legal action against Dershowitz for defamation, claims she only began to accuse him after lawyering up.

“She then met her lawyers, who ‘pressured’ her to falsely accuse Dershowitz, suggesting to her that she could make money by doing so,” the documents read.

Jeffrey Epstein’s self-proclaimed “sex slave” says she was farmed out to various men for sex during her years with the late financier — including Dershowitz.

Dershowitz claims the accusations are part of “broader conspiracy to subvert the judicial process for the purpose of making false claims against him in order to make a public example out of him, and extort private settlements from other, wealthier individuals associated with Epstein.”

“Committed to her lie, and using Dershowitz’s public invitation to sue as cover, Giuffre has now sued Dershowitz for defamation for calling her a liar,” the documents read. “But Giuffre is a liar. She has told numerous provable lies about her age, who she has met, whether she had emails concerning Dershowitz, and other fabrications, in addition to her false accusations about sex with Dershowitz.”

The lawsuit also claims David Boies of Boies Schiller Flexner — who was forced to leave the case after Dershowitz asserted he would call Boies himself as a witness at trial — took part in “an extortion and shakedown conspiracy” that targeted wealthy associates of Epstein’s.

“Giuffre, through her lawyers at Boies Schiller Flexner LLP, privately made an accusation against Leslie Wexner, the billionaire founder and CEO of L Brands and owner of Victoria’s Secret. David Boies personally met with Wexner’s lawyer in what Wexner’s lawyer and wife both described as a ‘shakedown,'” the suit reads.

“No public accusation against Wexner was ever made. This means that Wexner either submitted to Giuffre and her lawyers’ extortion conspiracy and paid the demanded hush money, or that David Boies came to disbelieve Giuffre’s claims regarding Wexner. If the latter, the Boies firm suborned perjury when Giuffre later testified under oath in a sealed deposition that she was sexually trafficked to Wexner.”

Dershowitz is suing Giuffre for defamation, intentional infliction of emotional distress, and seeking unspecified monetary damages.

Giuffre’s lawyer Chuck Cooper blasted Dershowitz’s filing as a “tired” rehashing of old attacks.

“Recycling the same false claims from his increasingly stale playbook, Alan Derschowitz has once again launched an attack on Virginia Giuffre and her lawyers,” Cooper said in a statement. “Lets call his counterclaim what it is: a failed attempt to make something old and tired look new. “