Jonathan Simpson, 32, of Newcastle Avenue, admitted the assault, which was on 24th June.
A trial had been set to go ahead, because Simpson initially denied the allegation. But on 30th August he changed his plea to guilty.
Prosecuting, Catherine Picardo said the door handle had come off in his hand as Simpson left the house after an argument with Michelle Sarvent.
“Without turning round he threw it back over his shoulder,” she said.
Defending, David Grant, said Simpson could not have known it was going to hit her.
Simpson was given a 12 month community order, 100 hours unpaid work and must pay £100 costs.