The driver of a delivery van was arrested after his vehicle travelled at least 2.5 kilometres on the wrong side of the Island Eastern Corridor before colliding head-on with a taxi in Causeway Bay.
The 26-year-old was arrested on suspicion of dangerous driving and refusing to provide a sample for a breath test.
Police received a number of complaints from motorists who saw the van travelling west in an eastbound lane of the expressway outside City Garden in North Point at about 3.45am.
Before officers could track it down, the van collided with an oncoming taxi outside the Police Officers' Club in Gloucester Road, Causeway Bay.
The 61-year-old cabbie, who had no passengers at the time of the crash, was trapped in the wreckage and had to be freed by firefighters.
Both drivers were injured but conscious when they were taken to Ruttonjee Hospital, where they were in stable condition.