The woman’s nose was left pouring with blood after she was attacked by Reiss Vieness, 27, during an argument.
Teesside Crown Court heard her face was so badly swollen that the hospital was unable to take an x-ray.
An argument developed at the couple’s home in Mulgrave Road, Hartlepool, in January last year after Vieness’s partner earlier confronted him about taking cocaine and deleting messages from his phone.
After the victim fell onto her knees Vieness grabbed her hair, lifted her head up and punched her three times in the face.
Prosecutor Richard Bennett said: “All three punches landed on her nose and broker her nose immediately.
"[The victim] described how her nose was instantly pouring with blood and how she felt it snap and then excruciating pain in her nose.”
She went to hospital but an x-ray could not be carried out until the swelling died down weeks later when she was still in pain.
She ended the relationship after another argument in February when Vieness said to her: “I’ll break your face like I did last time.”
The assaults came to light after she threw his belongings out on the street and he called the police himself.
Vieness, a fibre optics technician, pleaded guilty to actual bodily harm, common assault and possession of a small amount of cannabis on him when police attended.
Simon Walker, mitigating, said Vieness, who had no previous convictions, had acted totally out of character and was a valued employee.
He has since moved away.
Mr Walker said: “He was instantly remorseful. He’s lost his good name as a consequence of losing his temper as he did for a few seconds only.
"The lesson has been learned.”
Vieness, now of Paddock Way, Milton Keynes, was sentenced to 12 months in prison, which was suspended for 18 months.
The Recorder of Middlesbrough, Judge Paul Watson, said: “What you did on January 17 was completely disgraceful.
"She was entitled to look to you for affection and respect, not brutal violence.”
Vieness was also ordered to complete 240 hours of unpaid community work and given a six-month night time tagged curfew.