"'My agent wants to speak to you. United are coming for me, you have to make this happen.'"
Ighalo, his agent and the clubs spent the night negotiating and signing paperwork to get it through before the deadline at 7am Shanghai time.
Meanwhile, other clubs were calling asking Ighalo to sign for them.
"I told my agent 'this is what I want. I want to come here'," added Ighalo.
"He said: 'You're going to get a pay cut to go to United.'
"I said: 'I don't care. Make this deal happen. I want to go to United. I don't care how much is the pay cut, I know that, make it happen.'"