Gerald Dumas, 47, died after being attacked in an alley, robbed and set on fire. (Family photo)

A 21-year-old man has pleaded guilty to second-degree murder in the burning death of a Winnipeg man.

Gaston Genaille pleaded guilty in court on Monday morning.

Gerald Dumas, 47, was set on fire in an alley in the 500 block of Selkirk Avenue in September 2010.

His clothes and skin were on fire when officers arrived and they used a fire extinguisher to put out the flames.

Police said Dumas was walking alone down the alley when he was knocked down, robbed and then set ablaze with a flammable liquid.

Genaille was arrested hours after the attack and charged with aggravated assault, robbery with violence and breach of probation in connection with the case.

The charges were upgraded two weeks later when Dumas, who had been in the hospital, died of his injuries.

Second-degree murder carries a mandatory life sentence but lawyers still have to argue how long it will be before Genaille is eligible for parole.

The sentencing is expected to be handed down in January.