After almost seven hours of deliberations, the jury found Filitonga guilty of both charges.
As the foreperson announced the verdict, Filitonga appeared shocked and family members started crying.
A woman yelled: "I have something to say. I'm really disgusted with the verdict. My brother is innocent."
Other family members and friends appeared to fuming and some cried.
Filitonga's sister, Sharon Smith, said her brother was innocent and they were "very, very disappointed" with the verdict.
"He's the most loving, caring and honest man. This is not his character," she told the Herald outside court.
Smith said they would appeal the decision "whatever it costs".
Filitonga will be sentenced in May.
Over three days of evidence, the court heard how the couple met in February 2014 at Western Springs Park.
The complainant said he asked Filitonga about his HIV status and he told him he'd had a test three months earlier and was negative.
After two months of dating and during a holiday to the Philippines with friends, the man grew ill with nausea, aches, a fever and a rash which spread over his body.
During evidence he said he figured it was probably a tropical virus but later learned these were symptoms of seroconversion, when a person first develops antibodies for HIV.
The jury was shown texts from the man to Filitonga that October in which he asked what his sickness "really is".
"So please tell me now for real, have you got HIV or something? You have to tell me if you do. Something's not been said, I know it. Is that why you avoid having sex?"
A later text read: "Will you promise me to get that test and never take risks with your own or anybody else's life again?"
Prosecutor Jo Murdoch said the texts "speak volumes" that the man had no idea his lover was HIV-positive. She said it was an "implausible version of the evidence".
"These are the texts from a man who has not been told. These are texts from a man who wanted answers."
And they were not texts sent from someone who "vindictively fabricated" a lie after the relationship broke down, Murdoch said.
"Mr Filitonga was lying to [the complainant]. Every time they had sex, he was lying to him."
Murdoch also questioned Filitonga conduct after learning he had the virus as he failed to take medication and therefore didn't "take responsibility for his diagnosis".
But in his closing, defence lawyer Ross Burns said the jury had been asked to answer "really, important question based on some woolly evidence".
There was nothing independent of the complainant's evidence to support the Crown's case, he said.
"You can't just say, 'Well there we go, that's evidence of their responsibility'."
The lawyer told the jurors they had to be certain the man didn't have unprotected sex with another HIV-positive man - besides Filitonga - in the six months before they met.
Burns referred to the man's police interview where he told them he was at Western Springs Park - a "notorious place where gay men cruise" - to meet a man.
During the trial, the man said he was looking for his dog.
"He was going there looking for sex and if he was doing it then who can say he didn't do it the week before or the week before that."
Burns asked the jury: "Can you trust him?"
And while he didn't want to make the trial a "mud-slinging match" both men had unprotected anal sex with casual partners.
"What do you get from pointing the finger at each other, the answer is nothing. It works both ways."