A man has been convicted after Met officers swooped while he was on his way to meet a child for sex in south-east London.
Muhammed Zeeshan Ali, 33, had had been speaking to a 13-year-old girl on social media.
He had planned to meet the child outside Canada Water Underground Station on 7 February.
But officers knew of his plan and ambushed him at the meeting point.
Ali, of Rotherhithe New Road in Southwark, tried to destroy evidence on his phone by smashing it on the floor as he was tackled by police, the court heard.
He was charged the following day and appeared at Croydon Magistrates' Court on Friday where he pleaded guilty to attempt to engage sexual communication with a child and attempting to meet a child for sexual grooming.
Detective Sergeant Callum Mantell, from the Met's Online Child Sexual Abuse and Exploitation team, said: "Ali is clearly a dangerous predator who was using social media to attempt to sexually abuse a child.
"We carried out fast-time enquiries to identify him and ensure officers were waiting for him. Our investigation means he has been convicted and will now face the consequences of his actions."
Ali was remanded in custody and will be sentenced at Inner London Crown Court at a later date.
If you have any concerns about online child abuse we would urge you to call police on 101, or 999 in an emergency – police have specially trained officers who will listen and investigate where needed.
Alternatively call Crimestoppers on 0800 555 111 to remain anonymous, or report online. You can also report abuse and get support from the NSPCC – 0808 800 5000.