Young car thief Lee Pearson, 18, appeared from custody at Hamilton Sheriff Court following the incident on September 10 last year.
He admitted robbing Kieran Frew of the car in Caledonia Drive, Newarthill.
The encounter was in fact a pre-arranged meet-up between the two men who had been in touch beforehand.
But an allegation that he presented a gun and threatened to shoot Mr Frew was dropped.
Pearson had his not guilty plea to a charge of being concerned in the supply of cocaine accepted by the court.
Jennifer McCabe, prosecuting, said the men had arranged to meet.
It was stated that Frew drove into the street around 11.40pm.
No reason was given for the meeting.
Ms McCabe told the court: "Frew recognised Pearson who was dressed in a black jacket, jogging bottoms and gloves - and had his hood up.
"Pearson approached the driver's side window and said 'Give me the f...... car'.
"He made threats of violence and reached inside.
"He took the keys from the ignition.
"Frew got out of the car and Pearson got in and drove off at speed."
The victim was in left in a "distressed" state,
However, he found the presence of mind to raise the alarm at a nearby pub.
The next morning the Focus was found abandoned and damaged on a roundabout in Tannochside.
Pearson's DNA was on the keys.
These were found still in the ignition.
The car was written off and Frew's insurers wouldn't pay out.
He said he bought it for £3,500 last year
He had stated that he is demanding compensation from the accused.
Sheriff John Speir said Pearson, who also admitted driving the stolen car while disqualified, has "an abysmal record for a young man".
Sentence was deferred until next month and he was remanded in custody.