Polypady was charged in August 2011, after throwing chili powder on a man who he suspected of trying to steal from his car.
He said he noticed the man, identified as Manuel Belo, lurking at the back of his restaurant on Bloor Street.
He said he put up security cameras.
The tapes played in court showed Belo entering Polypady's vehicles.
Toronto police officer James Thompson, who investigated the incident, said in court that it appeared Belo "obtained something" from Polypady's car.
It was that incident that prompted Polypady to take things into his own hands.
Armed with a broom handle and chili powder, Polypady confronted the man.
A fight ensued and Belo was doused with chili powder.
Belo rode off on his bike with Polypady following in his car.
Polypady made a call to 911, which was also played in court.
During the call Polypady said he had thrown chili powder on Belo.
“Why did you put chili powder on him?” the 911 operator asked.
“He tried to hit me on my head and chest,” Polypady said.
Eventually Polypady was charged with assault causing bodily harm and assault with a weapon and administering a noxious substance..
The case has some similarities to the case of David Chen, the owner of a grocery store in Toronto's Chinatown.
In 2009 Chen chased down a man who stole from his store.
Chen was initially charged but a judge later threw those charges out.
The incident prompted Ottawa to revisit laws surrounding citizen's arrests.
Polypady's lawyer says his client's situation is different.
"The former one was a citizen arrest and this is self defence," said Calvin Barry. "And the Criminal Code was amended last year in 2012 and there have been some amendments to the Criminal Code when one asserts self defence as an accused person."
The trial will resume on April 18.