A Borders man cut the brake pipes on his ex-girlfriend's car after sending text messages with questions about her new relationship, a court has heard.
Alan Bell, 26, of Halliburton Place, Galashiels, admitted committing the offence in St Boswells in June.
The High Court in Edinburgh heard how Susan Hope drove off in her car and had to use her handbrake to stop it.
Judge Lord Kinclaven deferred sentence for background reports and remanded Bell in custody.
The court was told Ms Hope, 22, had driven her Ford Ka a short distance when she spotted a warning light.
Advocate depute Jane Farquharson told the court: "She attempted to brake but nothing happened and Miss Hope was forced to stop her car using the handbrake.
"An inspection of the motor car revealed that the front brake flexi hose had been cut."
During a search at Bell's home he pointed out to police the knife he used to inflict the damage and claimed: "I didn't want to hurt her.
"I just wanted to do damage to the car."
However, he was later released on bail by a sheriff but carried out a further act of vandalism to the car, damaging its exhaust.
He also admitted starting a fire at the home of a friend days later, after they argued over money when they had been out drinking.