Punji sticks. Me use poop and sharpness. Give big lizard tiny microbe. Big infection. Me eat meat and watch it slowly die painful horrible death weak from no food or water.

the Tyrannosaurus rex measured up to 43 feet long, stood about 12 to 13 feet tall at the hip, and weighed roughly 4 to 9 metric tons. Its skull alone could weigh up to 600 pounds, and it had a bite force estimated at 35,000 to 57,000 newtons.

BUT!

our intelligence

I could take it in a fight.

why humans absolutely dominate every animal on earth - our intelligence.

We like to think that about ourselves, but in my opinion, that’s not the whole truth. After all, there are other intelligent life forms as well (though it’s certainly debatable whether they’re just as intelligent, “differently” intelligent, or simply less intelligent). The key reason why we, in combination with our intelligence, dominate the planet is, in my opinion, cooperation within social groups beyond the (extended) family. Religions, states, laws… all mental constructs we use to ensure that we can cooperate within massive groups. As far as I know, no one else does this.

In our scenario here, this crucial component is missing: While a human is (quite likely) more intelligent than the T-Rex, he is, after all, just one individual, and his true strength lies in the community. If we were to place 50 people together in this setting, I believe there would be significantly less doubt about the outcome.

there's a very good reason why humans absolutely dominate every animal on earth - our intelligence

Gonna have to slight disagree on this one. I've always found out ability to organize and communicate in generalist situations to be far more valuable than individual intelligence (though that's also nothing to shrug at compared to other animals).

Naw, part of me is wondering if you'd be more likely to succeed in a 1-on-1 with the knife or a 3-on-1 unarmed. I still can't think of a good strategy, but I feel like wed stand a better chance that just any one of us out there.

Also our ability to run long distances. I have no idea on the speed of a T-Rex, but it may be possible to have it chase you long enough to wear it out.