Michael Phelps did not collect any Olympic medals Monday night in Rio de Janeiro, but he did deliver what will undoubtedly be one of the lasting images of the 2016 Summer Olympic Games.

Prior to a semi-final race in the 200m butterfly, Phelps was caught by cameras staring a hole through South African rival Chad Le Clos, who beat Phelps to win the gold in the event in London. Le Clos, who had been sitting next to the American, stood in front of him and began shadow boxing, which appeared to disturb his rival's mental preparation.

Phelps was not impressed, and Twitter exploded.