Lee Hamilton, who held only a provisional licence, lost control of his Peugeot 106 and smashed into a wall killing Kristoffer Brister.
Hamilton (23) was helped out of the badly damaged vehicle but ran away when police turned up at the scene in Leven, in Fife.
The speedometer of the crashed car was found to be locked at 69 mph following the collision in a road with a 30 mph speed limit.
Hamilton, of Den Walk, Methil, in Fife, admitted causing the death of Mr Brister by driving dangerously after drinking and colliding with a wall on November 30 last year at the A915 road at Windygates Road in Leven.
He also admitted that at the time he was committing an offence by driving otherwise in accordance with a licence and using the vehicle while uninsured or unsecured against third party risks.
Lord Uist deferred sentencing Hamilton to wait for the preparation of a background report.