The Manchester City forward, who could have enjoyed a Luis Suarez-like season last year had his campaign not been plagued by injury, unleashes a shot on goal with greater frequency than the Chelsea star but when it comes to accuracy, goals to shots and minutes transpired per goal scored, it is Costa who has the clear edge.
The Brazil-born Spaniard has been a revelation at Stamford Bridge.
For manager Jose Mourinho, he has gone from possessing a roster with no clear striking threat, to one that contains perhaps the most ruthless netbuster in British football.
Described by Arsene Wenger as an "animal" last year, Costa has demonstrated that he has what it takes to excel in a physical division. The 25-year-old, it seems, relishes battle. He's a street-fighter of a striker who is merciless inside the 18-yard area as all seven of his Premier League goals this season have been scored from inside the box.
If it wasn't for the heroics of Costa, the press would be penning the praises of Aguero who has struck thrice from just two starts.
If Costa is a more traditional 'English' centre forward, like a back-alley Alan Shearer, then Aguero is a complete striker capable of providing key passes, beating an opponent with a mazy run and finishing from just about anywhere.
Both players are on a hot streak right now, but who will emerge with the knockout blow when their tribes collide come Sunday afternoon?
Manchester City host Chelsea at the Etihad Stadium on September 21.