Jamie Cox was sentenced to 26 weeks for common assault after he attacked Viktoria Gribovskaja at her home in Lambeth, south London last year.
The Swindon-based WBO European super-middleweight title holder had denied assault.
His sentence was suspended at an appeal at Croydon Magistrates' Court.
The 29-year-old boxer, who appeared in court under his real name Jamie Russan was told his conviction still stands, but that his prison sentence will be suspended for 18 months.
Recorder Joseph Boothby told him he should treat the suspended sentence as "a turning point" and said: "Change your ways and think before you get angry with a girlfriend, or anyone else for that matter."
Cox had been sentenced to 26 weeks in prison for the assault and harassment charges, 20 weeks for violence to secure entry and 12 weeks for criminal damage, to run concurrently.
He is currently ranked number four in the world and is also a Commonwealth Games light welterweight champion.
After the hearing, Cox said: "I just want to get back to normal and to fight for world titles. I do not really treat today as a success."

Asif Kahn, who worked at Oldknow Academy in Birmingham, had faced allegations of misconduct.
A National College of Teaching and Leadership panel heard the allegations against him in November, although Mr Khan did not appear at the hearing.
The Professional Conduct Panel has said it did not find the case proven.
Oldknow Academy was one of several schools investigated amid claims of a Muslim hardliners' plot to control them; known as the Trojan Horse affair.
More on this and other stories from Birmingham and the Black Country
Mr Khan had been accused of agreeing "to the inclusion of an undue amount of religious influence in the education of pupils" at Oldknow, on or before 31 July 2014.
The accusations had included telling some male pupils to change for PE in a cupboard so they would not show their thighs, banning children singing during a production of The Wizard of Oz and turning his back on a woman as she offered to shake his hand.
He was also accused of sharing his personal beliefs with the children, for example telling the children they were not allowed pet dogs as they were Muslim.
A fellow teacher, former-acting head teacher Jahangir Akbar, was banned from teaching indefinitely in January, although he can apply to have his ban set aside in five years time.

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The man was identified by judicial sources as Chinese-American Xiyue Wang, a 37-year-old researcher from Princeton University.
Wang was arrested last August as he tried to leave the country, according to the judiciary's news agency.
The US State Department called on Iran to release all those held on "fabricated" charges.
The sentence was announced on state TV by deputy judiciary chief Gholamhossein Mohseni-Ejeie.
Mizanonline, the Iranian judiciary's official news agency, said Wang was part of "an infiltration project" that sought to gather "highly confidential articles" for US and British institutions including the US State Department, Princeton University, Harvard Kennedy School and the British Institute of Persian Studies.
"Before his arrest he was able to digitally archive 4,500 pages of the country's documents while under covert surveillance," the agency said.
Earlier this year, the authorities in Tehran said as many as 70 people they described as spies were serving sentences in the capital's jails.
The identities of only a handful have been made public.
"This person, who was gathering information and was directly guided by America, was sentenced to 10 years in prison, but the sentence can be appealed," Mr Ejeie said on Sunday.
He said the decision was taken by an Iranian court, without giving any further details.
In a statement, the US Department of State did not refer to any specific person but called on Iranian authorities to release all foreign citizens it is holding "unjustly... so they can return to their families".
"The Iranian regime continues to detain US citizens and other foreigners on fabricated national security-related charges," an official said.
A champion boxer who was jailed for breaking into his ex-girlfriend's flat and attacking her has had his sentence suspended.
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