Police said the driver was in Derham Street about 9pm and they believe he was involved in an altercation with two male youths before he was attacked.

Police said the driver was slashed and fled the scene in his cab. The cab then crashed and injured a 19-year-old man.

Detective Sergeant Tom Arnot of the Monash crime investigation unit said no one was in the cab with the driver at the time of the crash and they do not know if the 19-year-old was involved in the attack.

Ambulance spokeswoman Susannah Wilson confirmed paramedics treated the 27-year-old taxi driver for a deep cut in his right cheek.

"Paramedics gave him some pain relief and bandaged his wound. He went to Box Hill hospital in a stable condition."

She also said the 19-year-old was placed on a spine-board and another ambulance took him to The Alfred hospital in a stable condition.

Police are appealing for witnesses to come forward.

Anyone with information can call the Monash police on 95678910.