During his trial last year, the court heard that Wardlaw had never met or spoke with the woman before he launched the attack. Witnesses claimed he had taken large amounts of ice before the incident.
Although Wardlaw didn't contest killing Ashcroft, he claimed it was manslaughter. However, he was found guilty of murder by a jury after just two days of deliberation.
He was sentenced to 22 years and will be eligible parole in just over 15 years.
In handing down her sentence, Justice Rita Incerti described the murder as 'spontaneous and intense'.
She also acknowledged that Ashcroft's family had suffered greatly from the impact of her death.
'They have lost a loving mother, grandmother, sister and friend,' she said.