While this student may seem to have achieved domination of the subject, in fact all achievement has been made using plagiarism.
In this context, "dominated" means to have control or influence over something or someone to a significant extent. It often implies having power or authority in a situation.
Donner dominated this year's Reindeer Games.
It dominated the distant skyline standing at least twice as tall as the other builidngs.
Hatshepsut was the first female pharoah in a male dominated society
The towering edifice dominated the skyline of the city. An impressive edifice was built on the mountainside to house the presidential museum.
His visual style seems trapped in a universe dominated by references to Superman, video games, and old rock bands.
It was dominated by the Gods
The mighty forces of the Horde dominated the lands of Azeroth for years.
Women have always faced negative attitudes in jobs that were traditionally dominated by men.
Marshlands are often dominated by grasses, rushes or reeds.
The word "dominated" is a verb.
That sentence is grammatical, but it is a bit too long and unnecessarily complicated. How about this: Prior to 1994 the Cali and Medellin cartels dominated Colombian cocaine traffic.