So, a little bit of pseudo backstory first.
Imagine mother nature would be some godly being, that actually exists. Somewhere. In spiritual form.
Now imagine humankind would be a big thorn in her eye, as we've ruined the ecosystem to an unrecoverable amount. (Yes, I'm talking about nowadays) She wants to take countermeasures. So, in order for nature to fix itself, she transforms every animal to a twice as big being. Well, actually it's 2 times the height, 2 times the length and 2 times the width, resulting in 8 times the size all in all. The physical abilities scale accordingly of course.
The transformation of all animals (or brain containing living beings, if you like so), except humankind of course, happens worldwide at the same time and needs only a minute or so and is permanently. Now imagine there would be enough food for them. It is a slightly fictional version of our earth after all and, well, mother nature sure wants to keep her children alive.
Yes, I'm talking about our very earth, with everything as close to real life as possible, with the exceptions mentioned above.
To my question: Would humankind with the help of modern technology be able to remain the dominant species of the world in this scenario or would we be replaced by animals at some point?
(Question inspired by the raptor-theory of Jurassic Park III)