South African state prosecutor Gerrie Nel asked the judge in Oscar Pistorius' murder trial to reject the Paralympic and Olympic track star's defence because it was "devoid of any truth".
Mr Pistorius is accused of murdering his girlfriend Reeva Steenkamp at his home in Pretoria on Valentine's Day last year.
If convicted, he could face life in prison.
Since the trial opened in early March, Mr Nel has portrayed Mr Pistorius as a gun-obsessed hot-head who shot 29-year-old Ms Steenkamp four times through a locked toilet door where she was taking refuge after a heated argument.
The defence team says the track star was a vulnerable and caring boyfriend who killed Ms Steenkamp in a tragic accident after mistaking her for an intruder hiding behind the door.
"We will argue that the accused's version should be rejected," Nel told the Pretoria court during his closing arguments.
"If the accused version is rejected it means my lady that there was no perceived intruder whatsoever."
Mr Pistorius sat impassively through the opening minutes of the proceedings, which are expected to last two days.
After that, Judge Thokozile Masipa, who has more than 4,000 pages of evidence to review, will retire to consider her verdict.
Even if he is not found guilty of premeditated murder, Mr Pistorius could still be convicted and jailed on alternative charges of murder or culpable homicide.
The trial, which began on 23 March, was adjourned a month ago after the court heard evidence from a total of 37 witnesses.
The defence has sought to portray Mr Pistorius as obsessed with safety, a result of a difficult childhood and his disability, factors which they argue explain his reaction the night he killed Ms Steenkamp.
Mr Pistorius, a gold medallist Paralympian, rose to international fame when he competed alongside able-bodied runners at the 2012 London Olympics.