Two blue corners, two goalscoring heavyweights: Stamford Bridge is the stage for a sharp-shooting super-fight.
This weekend, the top marksmen in the Premier League come face to face.Â
Diego Costa, Chelsea's growling talisman, leads everyone else in the division with eight goals from his 10 appearances to date. But Romelu Lukaku is not far behind.
The one-time Blue turned Goodison Park favourite has the chance to silence his old club's fans - and show Antonio Conte just what he's missing after a failed summer bid for his services - when Everton go to Chelsea this weekend.
It is a fascinating game within the game, the winner of which will almost certainly influence the overall outcome in favour of their respective side
DIEGO COSTA: A SENSE OF BELONGING
Costa goes into the game in sensational form. Still the archetypal bully, the Spain international has found a way of channelling his inner aggression away from needless confrontation and towards the back of opponents' nets.
Benefiting hugely from Antonio Conte's switch to a 3-4-3 formation, and the service which comes with it, the Brazil-born striker has thrived on being the focal point for the attack without finding himself detached.
In the 4-2-3-1 system used by Jose Mourinho during his ill-fated final half-season at the Bridge, Costa became isolated. Frustrated, his performances dipped. And so he drew the ire of his manager. The vicious cycle exploded in a tunnel dust-up at half-time during a clash with Maccabi Tel Aviv a little under a year ago.
Costa, who at the time had only scored seven goals in the space of 12 months, took both barrels from the Portuguese.Â
'He is not reading the game properly in these actions,' Mourinho told the press. 'That was my opinion. As a striker he must read. You have to play not when you have the ball, but when others have the ball.
'You have to anticipate things and read the game faster. Everything is an accumulation.'
Fast forward to today, though, and there is little doubting Costa's reading of the game.
At Watford he made space for his winning goal by catching his marker unaware on halfway after seeing a pass being eyed up by Cesc Fabregas. In the home victory over Leicester, aided by some unusually slack Foxes defending, he freed himself at a corner to bundle home.
His movement and link-up play has improved exponentially, too. He is the cog for an attacking unit which moves with grace, ingenuity and purpose. And it's hard not to tie his upturn in form to Conte's arrival.
Costa has spoken previously about his admiration for Diego Simeone, the Atletico Madrid coach who he thanked for instilling confidence in him. Mourinho's approach actively sapped it from the forward, whose histrionics became more routine than goal celebrations during the Portuguese's reign.
However he's done it, Conte has made Costa feel wanted again. And with that sense of self-worth comes confidence. And with that... well, we've all seen first hand what comes next.
Costa isn't just a bruiser, he's a multi-faceted, technically excellent forward, capable of barging his way to a cross or producing a finish of substantial beauty - cases in point being his spectacular scissor kick at Swansea, a first-time finish at Hull and stunning free-kick at Southampton.
He's fitter, as well - scoring late and running long distances for his team. His 627 sprints are almost double the number accumulated by Lukaku so far this term, while he's upped his goals-per-minute from a miserly 198 last year to better than one every 90 minutes this.
Costa's goal at St Mary's was his 40th in the Premier League, coming in his 64th appearance. Despite his drought under Mourinho, he has reached that mark seven games earlier than Sergio Aguero of Manchester City.
His is a stark reminder of how important managers really are. And he shares difficult experiences of Mourinho with his adversary on Saturday.
ROMELU LUKAKU: THRIVING ON MERSEYSIDE
When the Belgian moved on loan to Everton in the summer of 2013, it was because he found his route to the Chelsea first team blocked.
Blocked by Fernando Torres, blocked by Samuel Eto'o, blocked by the notion that Mourinho was not about to give him a look-in any time soon.
He manufactured a move to Merseyside and that proved to be as astute a decision as a 20-year-old footballer is likely to make.
Lukaku has made himself hot property. So hot, in fact, that figures breaching the £75million barrier were mentioned in relation to a potential move back to Chelsea over the summer.
That never materialised - thanks in part to the intervention of Ronald Koeman and in part to the sense of purpose that the striker has at Goodison. It is the same sense of purpose which Costa is living off 250 miles further south.
This season, despite a brief sojourn through injury, Lukaku has continued his prolific march towards the top of the Premier League goalscorers' chart.Â
After breaking his six-month domestic scoring duck with a hat-trick at Sunderland so composed it made you wonder just how he hadn't been doing it every single week, his bullish ambition back.Â
The arrival of Yannick Bolasie has played a massive part. The pair's shared heritage - Lukaku is of Congolese descent while Bolasie is a DR Congo international - has evidently helped, and the pair have created five goals for each other already this term. That's more than any other combination in the top flight.
Most importantly, perhaps, Lukaku's smile is back. And the Lukaku grin should strike fear into opposition defences.
Statistically, his influence is broader than Costa's at Chelsea - Lukaku has made more chances (19) than the Blues man, contributed more assists (three) and has a superios shooting accuracy (74 per cent) - but the two players' importance to their respective sides is almost identical.
Lukaku, like Costa, is at the heart of Everton's attacking unit. And he's not shirking his responsibilities, creating on average one chance every 39 minutes for the Toffees this term. Costa, for what it's worth, makes one every 73. Â
And so we come to Saturday and Lukaku's encounter against the team which signed him, sold him and failed to bring him back.
'It will just be a normal game,' he's insisted this week.  Whatever you say, Romelu. Whatever you say. Mail Online