Another man was also robbed in the incident, which happened on Potternewton Lane at about 3.45am.
A mobile phone was taken and police say they are seeking two suspects in connection with the crime.
One is described as white, skinny, about 5ft 11in tall and in his late teens or early 20s. He spoke with a Leeds accent.
The second suspect is described as white, of large build and aged in his late teens or early 20s. He had light brown hair cut in a grade two style.
Both suspects were wearing casual sportswear.
Leeds CID’s Det Insp Mark Atkinson said: “This was a particularly nasty attack which has left one person in a serious condition in hospital and I would appeal to anyone who witnessed the crime to come forward.”
Witnesses or people with other information are asked to ring West Yorkshire Police using the force’s 101 number and quoting log reference 295 of May 8.