In the blue corner, Sergio Aguero of Argentina. Back in business, fit again and firing after injury and hotly-fancied to add to his 19 goal tally for the season so far.

In the red corner (well yellow and blue), Alexis Sanchez of Chile. A £30m man who has paid back his hefty transfer fee already; exceeding even the loftiest of pre-season expectations with his 18 goals, copious assists and a seldom-found and whole-hearted desire to play in EVERY single game.

Aguero and Sanchez were worth the admission money alone at the Etihad Stadium - they belong to that magical category of players who make impressionable young fans fall in love with the game.

But in the first-half just one of the pair made any impression. The opening 45 minutes was a collector's item in itself - a modern Arsenal team travelling away to one of the big teams and dominating proceedings.

Goalkeeper David Ospina was redundant, quite incredibly, as Arsenal controlled the game and, better yet, gained the lead through a Santi Cazorla penalty after Nacho Monreal was brought down - how easily is another debate - by Vincent Kompany.

But that seemed to be the only moment when Sanchez wasn't involved. The Chilean was holding the baton, conducting the orchestra and yet also playing some solos of his own. 

Fernandinho had been assigned the task of minder. Early on, Sanchez played the role of little silver ball to pinball machine bumper.

On six minutes, he showed immaculate chest control to bring an Arsenal move infield but the Brazilian snatched the ball. Game over.

Sanchez would have to be persistent. He mainly occupied the open acres on the left but willingly drove inside. At one point, he thrillingly squeezed between two blue shirts only to be swallowed by four more on the edge of the box.

As has so often been shown this season, Sanchez is indefatigable. One minute he was performing defensive duties, dispossessing James Milner and knocking it out for a throw, the next he was charging down Martin Demichelis as he hacked clear.

As Arsenal sat back a little more following Cazorla's penalty, Sanchez refused to follow suit but his forward charges increasingly led down blind alleys. Fernandinho started to take control and perhaps the Chilean might have dropped back more to help the increasingly-stretched back line.

But what of Aguero? Frankly, he was anonymous. For a side who found themselves five points behind leaders Chelsea after Saturday's action, they had surprisingly little impetus.

On 34 minutes, the Argentine positioned his body to win a corner - set-pieces were pretty much their only threat in the first-half - but it was his first contribution in about 25 minutes.

Ironically, the corner was headed away by, you've guessed it, Alexis Sanchez.

(dailymail.co.uk)