single paw

An above average adult male american black bear can weigh over 500 pounds, and easily produce half a ton of force with a single blow(standing on hind legs an putting weight behind it, would produce a lot more). But yeah, a decent sized male lion would be a decent match for an average sized black bear. Depending on hibernation state(aka fat reservers and thickness of the neck).

I love big cats, and would probably bet on it out of solidarity, but most bears cran crush the skull of a big cat with a single blow. My favorite/most horrible example is from the 19th century, when they put a 10ft bengal tiger against a 1500 pound grizzly. It did not last long.