The former Saved by the Bell star stands accused of one felony count of reckless endangerment and misdemeanour charges of disorderly conduct and carrying a concealed weapon for reportedly pulling a knife on Casey Smet in December (14).

Diamond denies the charges, claiming he was defending his partner Amanda Schutz, who is also facing a misdemeanour disorderly conduct count over the incident.

On Friday (29May15), the 38-year-old actor testified about the incident, saying, "I looked in my hand and saw I had a pocket knife. I said, 'Let go of my wife,' and pointed in her direction with the knife. At the moment I feared for her safety and her life. It was a lot of blood."

He continues, "I opened the pocket knife as a deterrent, thinking this will make them let go of my wife. The guy, at that point, saw I had a knife in my hand and immediately let go of her.

"I didn't swing or motion the knife towards him at all. I think he injured himself when he grabbed me."

Diamond's testimony, on the third day of the trial, took place a day after the jury was shown the bloodied T-shirt, sweater and damaged coat Smet wore on the night of the clash.

It is not clear if Diamond and Schutz, who has also pleaded not guilty for her involvement in the fight, are actually husband and wife, as suggested by the actor's testimony. The couple was engaged to wed at the time of the Christmas bust-up.