In its decision, the Ontario Court of Appeal rejected arguments from Michael Anderson that the sentence for his "horrific" crime was uncalled for.
"The circumstances of his crimes ... were especially egregious and aggravating," the Appeal Court said.
In April 2010, Ontario Superior Court Justice Todd Ducharme imposed the life sentence — rare for a first offence — after Anderson was convicted of aggravated sexual assault, attempted murder, unlawful confinement, threatening death and breaking and entering.
Under sentencing guidelines, the life sentence means Anderson would not be eligible for parole for seven years.
Court records show Anderson, who was then 26, broke into the elderly woman's west-end Toronto home early one morning in October 2005.
He threatened to kill her if she didn't submit to sex and cut her telephone line when she tried to call for help.
Over the course of an hour, Anderson raped the terrified woman, stabbed her three times in the abdomen with a knife from her kitchen, slashed her face and beat her, all the while ignoring her repeated pleas that he stop, according to the court record.
The attack only stopped when the victim managed to escape to her balcony and call out for help, and Anderson fled.
In a victim-impact statement, the woman said, "Brutal violence was done to my soul and body."
The defence called for 12 to 15 years but at sentencing, Ducharme described the attack as "degrading" and "extreme."
He said the "excessive violence" went well beyond anything needed to force her submission and found Anderson had shown "a callous lack of empathy" toward the victim.
"After anxious consideration, and taking into account the circumstances of both the offence and the offender, I have concluded that ... the facts of this case are so bizarre and shocking, that I can infer from the circumstances of the offence itself that (Anderson) poses an ongoing danger to the public," Ducharme decided.
"Thus, I am of the firm view that the appropriate sentence ... is imprisonment for life."
Anderson maintained on appeal that Ducharme was wrong to impose the sentence because the Crown had withdrawn its application to have him declared a dangerous offender — which it did because he refused to undergo a psychiatric assessment.
But the Appeal Court found Ducharme had properly weighed the various sentencing factors, including that Anderson was a first-time offender and there was no evidence of a violent past.
Overall, the judge was obliged to, and did, consider the full circumstances of the offences and the offender, the Appeal Court found.
"This included the available indicators of the appellant’s future dangerousness and the random and gratuitous nature of his attack."