Police say that around 8:30 p.m. on Saturday, a 58-year-old man watched a hockey game at home and then went to the Kitsilano Beach area.
When he returned home two hours later, police say the man was dazed and confused, suffering from what appeared to be a minor head injury.
His told his partner he'd been in a confrontation with someone at the beach but couldn't provide any details.
Police say he was found unresponsive at home the next day and rushed to hospital, where he remains in critical condition after having two surgeries.
The white man with a dark complexion was wearing a New York Yankees baseball cap, an orange T-shirt, cargo shorts, flip flops and carrying a black backpack.