Tennis star Nick Kyrgios on Friday pleaded guilty to assaulting a former girlfriend, but avoided a conviction for what the magistrate called a "single act of stupidity".

The Canberra magistrate dismissed the assault charge against the 27-year-old Australian player.

Appearing in a Canberra court, the Wimbledon finalist admitted assaulting then-girlfriend Chiara Passari on January 10, 2021, by pushing her to the ground after a heated argument.

Passari lodged a complaint with police 10 months later, after they had broken up, lawyers told the court.

In a statement read to the court, Passari said she had been severely traumatised by the incident, experiencing severe weight loss, staying in bed day and night – unable to sleep or form new romantic relationships.

Lawyers for Kyrgios had appealed to have the charge, one count of common assault, dismissed on mental health grounds, arguing it was an isolated incident and out of character.

Psychologist Sam Borenstein told the court Kyrgios suffered from recurring major depression, which included black periods, thoughts of self harm, insomnia, agitation and feelings of guilt.

Borenstein said the tennis star had relied on alcohol and drugs as a means of coping, but was now making progress in dealing with the issues.

Magistrate Beth Campbell heard that appeal but ultimately dismissed the charge.

Campbell said Kyrgios acted poorly but the offence was not planned or premeditated and was a "single act of stupidity" by a young man attempting to extricate himself from a tense situation.

Kyrgios was said to have shoved Passari, who was preventing him from leaving her Canberra apartment.

"I do not record a conviction against your name, I do not find any necessity to place you on a good behaviour bond," Campbell said.

Kyrgios had hobbled into court in Canberra with a pair of crutches and a brace on his knee, after suffering a "gruesome" injury that sidelined him at last month's Australian Open.

He was flanked by his current girlfriend Costeen Hatzi, an interior designer, and his mother Norlaila. (AFP)