Since his long-rumored and long-awaited arrival in the summer of 2014 — remember, we passed on signing a striker in 2013 to wait for Costa to become a viable transfer target — Chelsea's fortunes have been directly tied to Diego Costa's.
In his first season at Stamford Bridge, he set the tone for Chelsea's title-winning campaign by scoring seven goals in his first four Premier League games, finishing with 21 despite nagging hamstring injuries and several suspensions. In his second season at Stamford Bridge, he was a glaring symptom of Chelsea's malaise. Overweight and seemingly more concerned with picking fights than scoring goals, he managed just three Premier League goals before Christmas. His form did improve under Guus Hiddink, and fortunately, he's picked up at the start of this season where he left off with the interim manager. The goal against Hull on Saturday was his sixth already this season, which at least temporarily makes him the Premier League's top scorer (one ahead of Aguero, Lukaku, and ... Michail Antonio?).
Conte has obviously been very happy with all this, though he highlighted Costa's contributions beyond just the goal as well.
"For him [Costa] and for us it is fantastic. He has scored 6 goals for us, but I think that Diego has the opportunity in every game to score goals, but it is important not only that he scored a goal, but also that he worked for the team."
"For me, this is the most important thing, together with Willian and Hazard. It is important to work very hard and when you work very hard you have the opportunity to score goals."
"I am pleased not only for him, but for Willian and Hazard, they played a good game, a good performance, the right intensity. They tried to do what I want."
"I am pleased for all the players because we finished with a clean sheet. It is not normal to concede three or four goals. To finish with a clean sheet is very important."
-Diego Costa; source: Goal
Costa managed to avoid a yellow card as well, which means he'll be available for the match against Leicester City after the international break. He has a long way to go to avoid at least a one-match ban at some point however — he'd have to go without a yellow card the rest of the calendar year. Perhaps he can time it so that he gets banned for the EFL Cup match against West Ham, which means avoid a yellow in the next match against Leicester and then riling up a few emotions when Mourinho and Manchester United come to the Bridge the following weekend.
But for now, let's enjoy Diego's latest "beautiful golazo":