Frustrated with Pistorius's frequent crying in the witness box, prosecutor Gerrie Nel toughened his questioning and accused the Paralympic star of crocodile tears.
"Mr Pistorius, you're not using your emotional state to escape, are you" he said after the athlete broke down under questioning on one of several occasions today.
"You're getting frustrated because your version is improbable and you're getting emotional," he said.
During six days of testimony, Pistorius has often appeared harrowed when evidence has turned to the moments before and after he fired the four shots that killed Steenkamp.
Today he again burst into tears when he re-enacted his high pitched call for supposed intruders to out of his house.
Nel claimed Pistorius was crying because he knew he was shouting at Steenkamp and not a supposed intruder, putting the state's case that she was preparing to leave after an argument when she was shot.
"You know exactly, you fired at Reeva. These other versions cannot work, you fired at her, you did. Why are you getting emotional now" Nel said accusingly.
"I did not fire at Reeva," he said, weeping and forcing another adjournment.
Pistorius often looked pale in the witness stand, his shoulders hunched forward.
His lawyer at one point intervened to ask Judge Thokozile Masipa to prevent emotive questions from being asked and re-asked.
Pistorius's defence was picked apart throughout the day.
He has repeatedly claimed that he fired the shots accidentally, even though he feared there was an intruder behind the door.
"My Lady I didn't have time to think. I heard this noise, and I thought it was somebody coming out to attack me so I fired my firearm," he told the court.
Nel responded: "Your defence has now changed, sir, from putative self-defence to involuntary action. Is that what you're telling me"
"I don't understand the law, Ma'am, what I can reply and tell the court is what I'm asked and I can reply as to what I thought," Pistorius said.
During the relentless back-and-forth, Pistorius and Nel at times appeared to come close to bickering.
Nel accused the athlete of concocting evidence in his defence to cover up his girlfriend's murder.