An important London derby took place on Monday, with Chelsea visiting Emirates Stadium to face Arsenal. The Gunners looked the sharper squad this day, and a big second half breakout sent them to a 3-1 victory against the struggling champions.

Arsenal v Chelsea Starting Formations

The home squad started in a 4-2-3-1 formation, manager Arsene Wenger’s tried-and-true. A trio of top performers returned to the starting lineup for the Gunners, with Robin van Persie, Cesc Fabregas, and Theo Walcott all got the nod in the front 4. With Walcott starting, he took the right wing, while season standout Samir Nasri moved to the left wing. Alex Song and Jack Wilshere played behind Fabregas in the central midfield.

Manager Carlo Ancelotti brought Chelsea out in his preferred 4-3-3 alignment. The front three consisted of Didier Drogba at center forward, and Florent Malouda and Salomon Kalou on the left and right wings, respectively. Nicolas Anelka was not in the starting eleven, nor on the substitute list. Frank Lampard returned to the starting lineup for this important match

The first half action was carried predominantly by the Gunners. Chelsea’s attack in the first half was very tepid; their strategy seemed one of defensive security, trying not to get caught out by the Arsenal attack. Two 20 yard strikes from Chelsea stood out in the first half as their only true thread: a Drogba on a one-on-one run against Koscielny, and Malouda’s set piece attempt just before half that couldn’t weave its way through the maze of players in the area.

Arsenal stressed the right flank attack of Theo Walcott and Bacary Sagna against Ashley Cole and John Terry throughout the half. In fact, Terry was definitely a bright spot in the first half. Walcott was sprung several times, both down the touch line as well as across the outside of the area. Walcott giftedly moved the ball against Chelsea’s defenders, but between Terry’s play and Walcott’s lack of an incisive finish, his efforts proved fruitless.

As the half proceeded, Arsenal’s chances continued to accrue. Samir Nasri struck a perfect ball at the upper left corner from 22 yards, and Petr Cech was able to deflect it with his fingertips away from the goal. Finally, a run by Nasri up the left side was centered to Song. He passed to Jack Wilshire at the edge of the area, who hit what appeared to be a return pass. Three players were in the vicinity, but Song had the position to strike the ball well and just inside the right post. The half ended with the Gunners ahead by 1.

Chelsea brought of John Obi Mikel to start the second half, and replaced him with Ramires. Within 8 minutes, Arsenal had tripled their lead. Walcott escaped behind Ashley Cole, with the back undoubtedly wanting to help in the attacking half. Robin van Persie slid the ball through to Walcott breaking towards Cech. The winger snuck the ball to Cesc Fabregas, who dumped it into the gaping net. Less than two minutes later, Walcott stripped the ball from an unassuming Florent Malouda at midfield. Fabregas gathered the ball forward, and passed to Walcott into open space past a somewhat flatfooted Terry. Ivanovic could not recover in time and Walcott’s 18 yard blast past Cech to the far post gave Arsenal the 3-0 lead.

At the 56th minute, Malouda was subbed out for Kakuta, almost certainly to account for his gaffe that led to the third goal. Immediately, Chelsea responded. Branislav Ivanovic stretched past Koscielny and headed home a Drogba free kick to trim the lead to 2. The Blues’ final substitution came at the 61st minute, with the more offensive Jose Bosingwa entering for right back Paulo Ferreira. Ancelotti also changed into a very narrow 4-4-2 diamond, with Kalou pairing with Drogba up front. The four midfielders all maintained a central presence. Kakuta played the most forward, and Ramires in the defensive midfield position. Bosingwa and Cole providing the wing flank support.

Arsenal was able to hang on from that point forward though. There were some tense moments, but Wenger made some substitutions to help stem the tide of fatigue, as well as to bring a more defensive tactic. By the time the 80th minute rolled around, Arsenal was in a 4-1-4-1 defensive formation, with Nasri and Abu Diaby (a substitute for Walcott in the 76th minute) sunken into a flat-4 midfield, with Song right in front of the defense. To the left is the tactical diagram from the final 10-15 minutes of the match

Arsenal took advantage of the return to form of Cesc Fabregas, as well as a couple of mistakes by Chelsea, to forge closer to Manchester United in the title race. Chelsea’s descent continues to fuel the questions surrounding the job security of Carlo Ancelotti. Another tough match for the Blues’ against Bolton may become a harbinger of what the future for Ancelotti and the defending champions holds.