Fabregas (right) was injured for the match but entered the pitch at full time
Arsenal captain Cesc Fabregas has been cleared by the Football Association over charges relating to his conduct after the Hull FA Cup tie.
Fabregas, who did not play in the game, came on to the pitch after the final whistle and was later alleged to have spat at Hull assistant Brian Horton.
But an independent commission has now found there was not enough evidence on two charges of improper conduct.
Hull boss Phil Brown has requested a personal hearing to answer his charge.
Brown was charged by the FA following his comments about referee Mike Riley following the fifth-round replay on 17 March, which Arsenal won 2-1.
The investigation into the Fabregas incident was concluded last week but the FA did not want the results to become public until after Hull's crucial match against champions Manchester United on Sunday, where a win will guarantee their top-flight status.
It is relief because personally I always believed he was innocent
Arsenal manager Arsene Wenger
"The FA can confirm that, at a regulatory commission hearing, two charges of improper conduct against Arsenal midfielder Cesc Fabregas were found not proved," said an FA statement.
"One charge concerned his conduct after coming onto the pitch following the final whistle. The second charge related to an allegation of spitting."
For his part, Hull number two Horton was keen to keep his counsel when asked for his reaction by BBC Radio 5 Live.
"I only found out this morning," he said. "Until I speak to the League Managers Association (LMA) there is nothing I really want to say about it at the moment."
Wenger relieved as Fabregas is cleared
Arsenal manager Arsene Wenger welcomed the news from the FA, saying: "It is relief because personally I always believed he was innocent. That it has been confirmed by the FA is very good news for us.
"You have to respect that if the FA comes out and says there is nothing about the whole inquiry to punish Cesc Fabregas, then we have to respect that as well."
The Spanish midfielder, 22, had always maintained his innocence and has said about the spitting incident: "If I am suspended for that, my heart and my mind will be relaxed because I have not done anything wrong."
None of the match officials mentioned the incident in their reports to the FA after the game.
However, Horton had contacted the LMA to lodge a complaint before Hull and Arsenal were asked by the FA to submit their observations.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.