Honestly, it depends.
How are we measuring strength? Man may not be very strong, physically, when compared to, say, @Fyrius’ bear. But he is rather competent, which is why bears are in greater danger of extinction than we are in the first place. Not only are we good and making weapons, we also have enough free cycles to come up with agriculture, which is far sturdier a system than the ursine method of hunting and foraging, allowing for tremendous technological advancement because less time had to be spent finding the next meal.
That’s better spears, to be used along with our cataloged observations on how to deal with wild animals. Eventually, you’re back up to guns again. Even if you’re not, a man with some know-how can kill a bear with nothing more than a well-placed club.
That said, I know a guy who wrestled a wild boar to the ground, where he killed it with a knife. And Gore help you if you forget the mighty Steve Irwin, who grappled with crocodiles for the heck of it.
Read some Burroughs; he wrote at a time when Man was very proud of his intellect, and would not hesitate to tell himself as much.