Gofal Baziad was found guilty in May by a NSW Supreme Court jury of the February 2004 murder of Jason Palmer, his former friend and the ex-husband of his love interest.
Mr Palmer's body was found about three weeks later concealed in a sleeping bag and weighed down with sandstone rocks in the Nepean River at Menangle, in Sydney's southwest.
On Monday, Baziad was sentenced to a maximum of 24 years in custody by Justice Phillip Boulten.
"His disposal of the deceased's body in the Nepean River was a plainly callous act," the judge said.
Mr Palmer told his ex-wife Renny to decide between him and Baziad, the trial heard.
She chose her former husband.
Mr Palmer was later bludgeoned over the head with a patterned glass object before being stabbed multiple times in the torso, side and back in Baziad's Sydney apartment.
Baziad flew to Indonesia months later and continued to be in contact with Ms Palmer until she joined him overseas.
The pair returned to Australia in 2010, but the killer was only arrested in 2024.
"He left Australia, stayed away in Indonesia and declined to talk to the police … because he knew he was the person who killed the deceased and he wished to avoid detection," Justice Boulten said.
Ms Palmer gave tearful testimony during the trial about her efforts to find her ex-husband after he went missing.
The victim was seen for the last time in February 2004, when he walked out of his partner's home with Baziad.
Ms Palmer said she made numerous attempts to find him, even calling his drug dealer.
After the murder, Baziad continued to demonstrate intense jealousy whenever he believed Ms Palmer was the subject of another man's affections, Justice Boulten said.
In 2018, Baziad and his friend violently attacked Ms Palmer and her new partner in a car in Queensland using a hammer and a baseball bat, the judge said.
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