The convict, Ahmed Hassan, who came to the UK in 2015, denied intending to cause harm to people with the blast, saying to jurors that he made the device 'as a cry for attention'.
He was convicted by a unanimous verdict and will be sentenced next week.
He claimed that he was 'certain' that the homemade bomb would not explode, adding that he had tested a sample on the kitchen table and maintained that he never wanted to 'kill' people, The Telegraph reported.
The 18-year-old was known to authorities that he was 'trained to kill' by the Islamic State (IS), having told the UK Home Office officials.
Following the verdict, Commander Dean Haydon, head of Scotland Yard's Counter Terrorism Command, confirmed that a review into the Prevent programme in Surrey was now taking place with a view to implementing "any necessary recommendations".
"I describe Hassan as an intelligent and articulate individual that is devious and cunning in equal measures. On the one hand, he was appearing to engage with the (Prevent) programme but he kept secret what he was planning and plotting. We describe him as a lone actor," Haydon said in a statement after Hassan's conviction.
On the bomb's potential, he said: "It was only through good fortune that it only partially exploded. If it had, without a doubt we would have been dealing with many fatalities."
Hassan was arrested by the Kent Police, hours after the attack was committed at the Parsons Green Tube Station and was in police custody.
The IS had claimed responsibility for the attack. (ANI)