Pistorius’ guttural wailing and sobbing, prompted by his description of finding the lifeless body of Reeva Steenkamp behind his closed toilet door, brought proceedings to a halt early on Tuesday.

But his ordeal is far from over, with the state’s chief prosecutor Gerrie Nel expected to begin his cross-examination sometime on Wednesday.

A formidable opponent, Mr Nel once kept an accused police chief answering questions in the witness box for eight days before ultimately securing a conviction.

There have been many emotional and dramatic episodes in the trial so far, but nothing quite like Day 18.

As the double-amputee runner broke down, only two people appeared unmoved.One was the mother of his girlfriend and victim, Reeva Steenkamp.

The other was the trial judge. June Steenkamp has cut a stoic and silent figure throughout the evidence so far, and she remained emotionless on Tuesday as the man who killed her daughter completely fell apart.

She stared directly at Pistorius as he collapsed in anguish recounting the moment he realised it was in fact his model girlfriend on the other side of the door, not and intruder, and “she wasn’t breathing.”

Judge Thokozile Masipa was similarly unmoved, at times on Tuesday even appearing exasperated with the Olympic track star, whose voice became barely audible during segments of his evidence, tears flowing.

There have been many emotional and dramatic episodes in the trial so far, but nothing quite like Day 18.

Pistorius’ guttural wailing and sobbing brought proceedings to a halt early, but his ordeal is far from over. He faces a formidable opponent in prosecutor Gerrie Nel, who will likely begin his cross-examination sometime on Wednesday.

Mr Nel is a renowned cross-examiner, once keeping a police chief answering questions in the witness box for eight days.

As Pistorius was guided through the days, hours and minutes leading up to the fatal shooting by his barrister Barry Roux SC, it was clear Pistorius wanted the court to see a picture of relationship-bliss: the athlete was a man besotted with his beautiful girlfriend, and she was madly in love with the athletic hero.

Soppy text messages, romantic gestures of cooking and flowers, and self-confession: “I think if anything I was more into her than she was (into me) at times.” He said the pair had seen a future together, and talked about plans.

Desperate to neutralise the messages of anger and fear Ms Steenkamp sent after two fights before her death, Pistorius was quick to note out his flaws and highlight their arguments as fleeting and lovingly resolved.

The night before Valentine’s Day, February 13, 2013, Pistorius said he came home at about 6pm and his girlfriend was there, preparing dinner.

He spoke to her for a short time, before heading upstairs to have a bath, where he surfed the internet on his iPad. What was left unsaid was that electronic records reveal he was briefly on a pornography site at around 6.30pm.

On his version, he must have done that while Ms Steenkamp prepared his evening meal.

Nonetheless, the night was otherwise regarded by Pistorius as domestic bliss: the couple ate dinner at about 7pm, he helped her with a modelling contract she was about to sign, and they retired early.

With every lengthy, detailed sentence, Pistorius inched closer to the moment he fired the bullets that killed Ms Steenkamp.

He sobbed, and his voice became high-pitched as he fought back the tears that kept coming. It was an emotional crescendo to the most agonising moment of the trial so far, and the increasing noise from reporter’s keyboards only added to the drama.

With tears running down his face, he told the court in great detail how he woke up in the early hours to find his fans cooling the humid night still whirring and the balcony door and curtains still open. His girlfriend had rolled over and said, “Can't you sleep, my baba?”

These were the last words he says she spoke.

The paranoid, security-conscious Pistorius had effectively locked them into the master bedroom earlier that night, ever-fearful of intruders, and had asked Ms Steenkamp to close them as he fell asleep before her.

As he closed the curtains himself, he said a noise came from his bathroom, hearing what he thought was the sound of the window hitting its wooden frame.

“That's the moment that everything changed. I thought there was a burglar trying to gain entry into my home,” he said, voice thick with emotion.

Pistorius said he initially “just froze” but quickly swung into action, grabbing his 9mm pistol to “protect Reeva and I”.

Believing the phantom intruder could at any minute shoot him dead, Pistorius said he opened fire after hearing a further noise inside the toilet “that I perceived to be someone coming out”.

Ears ringing from the gunshots, he then made his way back to the bedroom still on his stumps, he said: “That’s when it dawned on me that it could be Reeva who was in the bathroom.”

He returned to the bathroom. “I didn't want to believe it could be Reeva who could be in the toilet.”

Pistorius claims he was “screaming and shouting the whole time” as he frantically put his prosthetic legs on, tried to kick down the door before bashing it with a cricket bat.

Openly crying, his voice pitched-high with emotion, he said he eventually got inside to find a bloodied, fatally wounded Ms Steenkamp.

“I sat over Reeva and I cried. I don’t know, I don’t know how long, I don’t know how long I was there for,” he said, his sobs intensifying.

“She wasn’t breathing.”

With that final statement Pistorius lost his composure entirely, putting his head in his hands and wailing like a man defeated.

The one-time South African golden boy was distraught and inconsolable.

After an adjournment, in which Pistorius was taken from the court under the embrace of emotional siblings Aimee and Carl, his howls still audible within the court, his barrister Barry Roux SC said he could not "in all consciousness" ask his client to continue with his testimony for the last half hour of the day.

Still, Mrs Steenkamp remained unmoved.

Judge Masipa quickly adjourned court until Wednesday morning.

Earlier, after changing into a white long-sleeve T-shirt and lycra shorts, Pistorius had removed his prosthetic legs and stood beside the toilet door, with its four bullet holes, which remains erected in the court room next to the witness box.

Neither he nor the wooden door are going anywhere just yet.

The trial continues Wednesday.