Nancy Ruth Allen, 51, has been sentenced to 35 years in prison for setting her ex-boyfriend on fire outside his home in Galveston, Texas, in November 2017

A Texas woman has been sentenced to 35 years in prison for launching a firebomb at her ex-boyfriend, setting him ablaze.

Nancy Ruth Allen, 51, carried out the assault on November 28, 2017, after getting in a fight with the current girlfriend of her ex-boyfriend of six years, Thelonious Haley, at his apartment in Galveston.

Haley said he told Allen to leave after she threatened to shoot him and the woman.

She then returned later that night and lured Haley out of the house by shutting off his power.

Surveillance video showed the moment Allen launched a 'firebomb' made of fuel-soaked rags at Haley before fleeing as he went up in flames.

Surveillance video showed the moment Allen launched a 'firebomb' made of fuel-soaked rags

Authorities said Haley survived but suffered severe burns to his face and body that required surgery and skin grafts.

He identified Allen as his attacker and she was arrested one week later.

The 51-year-old was sentenced on Monday after pleading guilty to aggravated family assault with a deadly weapon.

She will be eligible for parole after she serves at least half of her 35-year sentence.

Court records indicate that Allen has a number of previous felony convictions for theft, escape and possession of a controlled substance.

Those who know her told ABC13 that she had been harassing Allen for years.