And it supposedly happened here. But it was a case of Reno's problem -- not reasoning through the problem and making serious mistakes as a result. Try looking up "cold fusion."
Grad students don't often make revolutionary discoveries. And given that ARMIES of grad students have tried and failed for fusion power should be a clue that maybe it's not that easy.
It's fairly obvious what needs to be done for fusion to work -- the technical term is emittance reduction; essentially it means reducing the volume of a given sample and its temperature simultaneously. It's been tried left right and center. Don't hold your breath.
And even if it was to work, fusion power is not the clean limitless energy source hyped in the 50s. It is VERY dirty, potentially much worse than conventional fission, as D-T makes neutrons. Many, many, many neutrons.