Gary Travers, 43, was convicted of attempted murder, making threats to kill and false imprisonment following a seven-day trial at Portsmouth Crown Court.
Suicidal Travers had denied accusations he tried to kill Waterlooville psychologist Dr Georgina Ingall, 47, after she ended the relationship.
But after a day of deliberations jurors returned unanimous guilty verdicts for the charges of threats to kill and false imprisonment before judge Roger Hetherington directed the jury to a majority decision over attempted murder.
Travers, who bowed his head after being convicted of the first two charges, didn’t have to wait long before his fate was sealed as jurors returned minutes later to confirm Travers’ guilt for the most serious charge.
The defendant, dressed in a suit throughout the trial, was motionless after the result came back.
During the trial, the court heard how Travers launched two litres of petrol over his ‘terrified’ former girlfriend after luring her into his Audi TT before frantically trying to spark a lighter in a bid to kill the pair of them at the White Hart pub car park on Hambledon Road, Denmead, on Christmas Eve last year.
Travers gave Dr Ingall flowers and Prosecco once she was in the car but after being told the relationship was over he reached for a bottle which had been filled with petrol.
He told jurors he only ‘wanted to kill himself’ and not his former lover during the desperate struggle.
But eyewitnesses who testified in the trial revealed Travers' true intention as he grappled to keep Dr Ingall in the car after trying to spark the lighter.
Another witness said how the defendant revealed he had intended to burn himself and his ex-partner to death after the botched attempt.
Dr Ingall, during an emotional appearance giving evidence, said: ‘(Travers) was saying: “We’re going to die and we’re going to die together”.
‘He then got a lighter from somewhere and said “this is it” before starting to count down “five, four, three…”.
‘He kept asking me if I was “ready to die”.
‘It was very clear he wanted us to die together. He took the lid off the bottle and was violently shaking it everywhere.
‘It went down my face, into my mouth and eyes.
‘I was saying “it doesn’t have to be like this, we don’t have to die like this.’
After ‘fighting for her life’ whilst ‘hammering’ the passenger door window to escape after the door had been deliberately broken to trap her inside, Dr Ingall finally burst free of Travers with the help of a nearby delivery driver who pulled her free after the window suddenly opened.
Dr Ingall said: ‘He never intended us to leave the car - we were both meant to die.
‘I’m a very lucky lady to be stood here today.’
Meanwhile Travers, of no fixed address but who had resided in Hedge End, told jurors of his ‘heartbreak’ at the two-year relationship ending.
He repeatedly denied his intention was to kill Dr Ingall, claiming he wanted her to see him kill himself in ‘front of her’.
Travers, who had lived with Dr Ingall at her Waterlooville address before he was asked to leave for being caught taking cocaine, was remanded behind bars until his sentence hearing when he will discover the length of his jail term.
Travers’ parents and Dr Ingall did not wish to comment after the verdicts.