Fans blast Alexei Popyrin's winning celebration as he causes major US Open upset to defeat Novak Djokovic - but others claim it was 'no where near as bad as the Serbian's past behaviour'

The Australian, who is ranked 28th in the ATP tour rankings, let out a huge roar and held his arms aloft at the Arthur Ashe Stadium after he clinched a 3-1 victory over the Olympic champion.