The use of CRISPR-Cas9 for gene editing has the potential to be one of the most important technical advancements we've discovered this decade.
One of the first major papers on it, from 2012: https://www.ncbi.nlm.nih.gov/pubmed/22745249
I would second this. CRISPR is a potentially hugely influential tool which has massively changed research already, allowing production of novel strains much more cheaply. Not to mention the possibility for in Vivo genetic editing.
I would say is the biggest technical advancement in genetics ever.