Arsenal may focus on perceived elbow injustice but dominant Chelsea showed why they will be champions

The incident for the first goal will cause plenty of controversy but Arsenal would do better to be introspective rather than outraged

Marcos Alonso rises above Hector Bellerin to score the opening goal - but was it legal? (Getty Images)

In the same way that everyone suddenly became experts in Rioplatense linguistics around the time of Luis Suarez's verbal tangle with Patrice Evra, today was a day when the amateur biomechanics experts and kinesiologists came out to play.

Marcos Alonso's goal, the opener in a frantic, tense game at Stamford Bridge, was the worst sort of incident for clarity and the best for rolling sports news coverage simply because it was firmly embedded in the grey area.

Arsenal, their manager and their fans can (and will) point to contact being made between Alonso's arm and Hector Bellerín's head and scream about a clear free kick not being given. Chelsea can, with similar certainty, question how on earth Alonso is meant to jump with his arms glued by his sides like a 6ft 3in salmon trying to leap upstream.

The picture from before the header (below )shows both players using their arms to jump as high as possible. Discount this. It will not fit your narrative.

Indeed you can argue with all of your screengrabs, but a still picture very rarely does justice to the moving image and while a later snap of Alonso's forearm buried in Bellerín's face seems similarly affirming of his guilt, remember one thing: it isn't.

Hector Bellerin and Marcos Alonso both jump for a header (Getty)

Usually with contentious refereeing decisions the question should be "can you see why the official gave what he did?" rather than "do you agree with the decision?"

This will be lost in the fury and counter fury. And while Arsenal will feel unfairly punished by this - having conceded the goal and then lost one of their substitutions early in the game - they never really looked to be in this encounter.

Of more concern should be that, with this perceived injustice in mind, the Gunners should have kicked on and been stirred by this feeling. This anger.

Instead, Chelsea's dominance was convincing and rarely challenged, with the Gunners' best chance coming when Gabriel Paulista, of all people, rose in the box to head unmarked. He only succeeded in finding Thibaut Courtois's windmill arms. Arsenal's late consolation goal through Olivier Giroud would feel almost embarrassing.

Eventually the hosts' superiority paid with a second goal and it was stunning. Eden Hazard, picking the ball up in midfield, ran the long way round Francis Coquelin, shouldering the Frenchman away until he ended up performing something of a barrel roll, like a stunt double trying to dive in through the window of a moving car.

With Coquelin on the turf, Hazard ran at Laurent Koscielny, juking outside him before catching an early strike that looped over an over-committed Petr Cech. It was 2-0 and it was, undeniably, curtains - as this title race appears to be.

Cesc Fabregas' sensational third, loopy and wild, cemented the result. It emphasised the pain. It may, in part, further diminish the feeling of injustice over Marcos Alonso's goal but don't hold your breath.

The 'elbow' - what they said

Graeme Souness on Sky Sports: "He's only got eyes for the ball, it's not a foul."

Thierry Henry on Sky Sports: "Obviously I hope that Bellerin is okay but it is a fair challenge... It looks bad but it is fair."

Arsenal manager Arsene Wenger: "I think the goal was a foul, then of course Chelsea do what they like to do. Wait for you and counter attack."

Danny Mills on Radio 5 Live: "There is contact, but both players are coming for the ball. I don't think it's a foul."

Dermot Gallagher on Radio 5 Live: : “Good goal. He’s gone fairly and didn’t leap with the arm."