Wright said the case stems from an incident on Nov. 1, 2020, that began when Giggs and Greville were out with friends at the Stock Exchange Hotel in Manchester.
During the evening, Greville decided to end their relationship because of Giggs' behaviour and because she knew he had been cheating on her.
Greville left the hotel early, planning to return to the home she shared with Giggs, retrieve her belongings and leave before he came home, Wright said. Greville asked her sister to meet her at the house for support.
The plan failed because Giggs came home earlier than expected and argued with Greville as he tried to stop her from leaving. A physical altercation began when Greville took Giggs' mobile phone to use as a bargaining chip and Giggs tried to grab her device, Wright said. Greville's sister was elbowed in the jaw after she tried to intervene, he said.
"At that stage, we say, the defendant entirely lost self-control and he deliberately head-butted Kate, thereby causing swelling to her lips and bruising," the prosecutor said.