Chelsea picked up a significant 3 points via two set pieces, then held Arsenal off professionally.

Wenger started a similar team to the one that earned a point at the Etihad last week, except Thomas Vermaelen replaced Per Mertesacker, who dropped to the bench. Gervinho maintained his place ahead of Olivier Giroud upfront.

Di Matteo played his usual 4-2-3-1, this time starting with Hazard, Mata and Oscar all behind Torres, with Ramires and Mikel holding behind.  

This was a fairly even game that Chelsea saw out fantastically in the final 20 minutes.

Defensive Selection

Given how consistent Per Mertesacker has been in the opening games it was perhaps surprising to see Laurent Koscielny starting ahead of him partnering Thomas Vermaelen.  In truth, Wenger probably made the correct call prior to the match, as Chelsea's attacking trio of Mata, Oscar and Hazard are a mobile and fluid unit who would have benefited against a more static defence.  Furthermore, Mata and Hazard were drifting infield as inverted wingers to overload the midfield zone, which explains why Chelsea dominated the ball in the first half.  A mobile defence, despite the set piece errors, was probably the correct call prior to the match.

Arsenal target the right

The tactical highlight of the first half was Arsenal's tendency to play down their right flank. Aran Ramsay's selection ahead of Ox and Walcott was interesting- it appeared as if Wenger, like Di Matteo, was interested in using an alternative type of winger in order to help control the game too.  This also made for an interesting combination with Santi Cazorla, who was playing in his traditional 'central winger'- drifting out to the right flank to overload Ashley Cole, allowing Ramsey to come back inside and maintain a creative attack, drawing Chelsea's defenders around the pitch.  Gervinho was clearly conscious of this strategy as he too moved laterally across the pitch to exploit the space made, yet often his spacial awareness and first touch let him down.  

Both players were supported by Carl Jenkinson who played a very consistent support role, free to run forward because of Hazard's lack of tracking back and infield play.  By the end of the first half the highest pass completion combination was between Oxlade-Chamberlain and Jenkinson, and eventually the pressure told when Gervinho grabbed the equaliser in the 44th minute from a low cross on the right flank.

This is the second time Arsenal have clearly exploited a particular flank, and its interesting that they chose to ignore the one that Podolski, probably their best goalscorer, plays on.  The strategy works both ways, however. While Podolski is slightly neglected of the ball, he can often crop up at the back post in space when defences get drawn across the pitch from initial movement.  What's more, despite his attacking talent he's also been playing a disciplined defensive role which may explain his lack of time on the ball.

Crossing

Crossing too was a feature of the game.  Having gone a goal up Chelsea could afford to drop deeper, and with little space to exploit Arsenal needed someone to aim at in the final third.  Gervinho and Cazorla who had little chance of aerial success against Terry and Luiz, so it was imperative that Arsenal's wide players began to drill the ball in low in order to actually complete a cross.  Gervinho finally found the ball in space in the box from a low cross from Oxlade-Chamberlain, and slotted home to level the game at half time.

Stop Cazorla, stop Arsenal?

Having gone back in front Chelsea still had a substantial job in seeing the game out.  Instead of reverting to a narrow, compact and deep game plan they remained relatively positive and continued to move forward with their attacking players.  

Wenger tried to mix things up by moving Oxlade-Chamberlain into the middle, Walcott right, Giroud up front with Gervinho moving left.  But this seemed ineffective due to Chelsea's organised defensive play.

The key was the movement of Chelsea's holders, Ramires and Mikel, who stuck much closer to Cazorla and marked him out of the game.  Without his input Arsenal struggled to control the ball, and the game became largely fragmented with neither team creating much.  Arsenal's passing in particular was abysmal in the final 20 minutes, and one wonders just how important Cazorla is to the team's entire chemistry.  

Conclusion

Chelsea were impressive in defence and ultimately deserved their victory in the end. Arsenal can take some positives too though- they're still yet to concede a goal from open play.  To those who will openly criticise Wenger's decision to drop Mertesacker for Koscielny should also remember that Vermaelen gave away the two free kicks that Chelsea profited from;- who knows how Mertesacker would have dealt with Chelsea's attack?  What's more, Mertesacker's absence at set plays could have been constituted by Abou Diaby's height, so his injury was unlucky on Wenger's part.  Ultimately, other than those two goals, Arsenal maintained their strong defensive nature in open play and should remain encouraged with the evident changes to the team.

Chelsea have now taken 16 points from a potential 18 and are showing positive signs of launching a very genuine title winning campaign.  They should be hugely pleased with the strong defensive display shown in seeing this match because if they can maintain it, they can almost certainly rely on a set piece or one of their hugely talented attacking players to get them a goal in any match.