And so it turns out, there is more to winning the title than signing a goalkeeper from the champions. Who would have thought it?
After spending £10million on Petr Cech from Chelsea, the optimism was high. When Arsene Wenger beat his nemesis Jose Mourinho in the FA Community Shield, it went a little higher still.
Arsenal had finished the last campaign in such terrific form, bagged another FA Cup and Wenger had preached about the value of continuity and cohesion through pre-season.
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Mauro Zarate (centre) heads towards the away end at the Emirates to celebrate putting West Ham into a 2-0 lead against hosts Arsenal
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West Ham striker Zarate is followed by team-mate Aaron Cresswell as he leaps into the air to celebrate the Hammers' second goal
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West Ham's travelling supporters go wild inside the Emirates as Zarate is mobbed by his team-mates following his 57th minute goal
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Zarate, who spent an unsuccessful loan spell at Queens Park Rangers last season, makes it 2-0 with a low strike from 20 yards out
MATCH FACTS
Arsenal (4-3-2-1): Cech 4, Debuchy 5 (Sanchez 67 mins, 6), Mertesacker 5, Koscielny 5, Monreal 5, Coquelin 6 (Walcott 58 mins, 6), Cazorla 6, Ramsey 6, Ozil 5, Oxlade-Chamberlain 7, Giroud 5.5
Subs not used: Gibbs, Gabriel, Arteta, Ospina, Chambers
Booked: Monreal
West Ham: Adrian 7.5, Tomkins 7, Reid 7.5, Ogbonna 7.5, Cresswell 7, Oxford 8 (Nolan 79 mins, 6), Noble 7, Kouyate 7.5, Payet 8, Zarate 6.5 (Jarvis 63 mins, 6), Sakho 7 (Maiga 89 mins, 6)
Subs not used: Randolph, Collins, Poyet, Lanzini
Booked: Tomkins, Noble, Ogbonna
Goals: Kouyate 43, Zarate 57
Referee: Martin Atkinson (W Yorkshire)
*Player ratings by Sam Cunningham at the Emirates Stadium
Then, the serious business started.
West Ham turned up, with a new manager and a new muscular presence, Cheikhou Kouyate and Mauro Zarate scored either side of half-time, and a very different mood descended upon the Emirates Stadium.
Old problems linger on. Vulnerable at the back, lacking punch up front with Alexis Sanchez and with the unquestionably gifted Mesut Ozil neutralised by a 16-year-old making his debut.
Then there was Cech...
It was not like this at Stamford Bridge, where his goal area was so well insulated.
Cech was exposed more times in 90 minutes than he would expect to be in a month at Chelsea, and yet he must hold up his hands and accept some of the responsibility for goals which were soaked in defensive sloppiness.
The first was a free-kick, well delivered by Dimitri Payet and converted by a firm header by Kouyate, who escaped Nacho Monreal with minimal effort.
When he clocked the danger, Cech charged 'Superman' style from goal but was beaten to the ball and left to flounder around on the turf, somewhere near the penalty spot, as the ball settled into his net.
For the second Arsenal struggled to take the ball from Aaron Cresswell and, when they did, Alex Oxlade-Chamberlain was easily dispossessed by Zarate.
No-one closed him down, so Zarate, ridiculed for his lack of fitness on loan at QPR last season, took aim from 20 yards and found Cech napping on his line.
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West Ham midfielder Cheikhou Kouyate wheels away to celebrate after giving his side the lead against Arsenal late in the first half
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Kouyate gets a hug from team-mates Reece Oxford and Mauro Zarate after scoring his side's opening goal of the Premier League season
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Kouyate rises high to beat summer signing Petr Cech to the ball and head the visitors into a 1-0 lead in the 43rd minute
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Cech, a £10million signing from champions Chelsea, watches on as Kouyate's header flies towards the back of his net
West Ham youngster Reece Oxford played in a defensive midfield role against Arsenal, as you can see in his heat map below - CLICK HERE for more from our brilliant Match Zone
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The ball flashed inside the post as the 'keeper dived too late.
'Super, Super Slav…' and 'We're going to win the league' sang the West Ham fans. After their feeble surrender in the Europa League, no-one had predicted this.
New boss Slaven Bilic was an instant hero, as was new signing Payet and teenager Reece Oxford, at 16 years and 236 days the second youngest player to ever appear in the Barclays Premier League.
Holding in midfield, against Ozil, it was a debut Oxford will never forget.
Wenger, meanwhile, starts the season with a headache and a home defeat. His feel-good factor has vanished and he has to accept some of the blame.
It was difficult to find the logic in moving Santi Cazorla from a position, deep in central midfield alongside Francis Coquelin, where he has proved so influential this year.
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Arsenal midfielder Santi Cazorla finds himself surrounded by West Ham players during the first-half at the Emirates Stadium
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Germany international Mesut Ozil (right) tries his luck from a free-kick as West Ham's wall jumps to try and block his effort
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Hammers goalkeeper Adrian dives to his left to palm a shot away and keep the score level at 0-0 on Sunday afternoon
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West Ham striker Diafra Sakho (right) bursts forward with the ball as Arsenal midfielder Francis Coquelin chases him down
Perhaps it was to accommodate Oxlade-Chamberlain on the right, arguably his best position, while keeping Aaron Ramsey in the team to offer thrust and goal-threat from midfield.
The Ox was certainly bright and effective in the opening phase of the game, pepped by a goal at Wembley and Wenger's gushing pre-match comments, which billed him for a big season if he displays the 'dedication' and 'concentration' required.
Oxlade-Chamberlain went tantalisingly close with a swerving volley before a bubbling run and cross to the back-post which Cazorla met on the volley and nursed over.
Ramsey rattled the bar with an effort which clipped Cresswell.
Ten minutes before half-time, Cazorla moved back into the centre and was immediately beaten in the tackle by Payet, who fired over.
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West Ham boss Slaven Bilic gives instructions to his team from the touchline during his first Premier League game as a manager
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Arsenal midfielder Alex Oxlade-Chamberlain is sent tumbling after a tackle from summer signing Angelo Ogbonna
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Gunners captain Per Mertsesacker challenges goalkeeper Adrian and Hammers defender Winston Reid for an aerial ball
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Sakho falls to the fall after tussling with Arsenal defender Laurent Koscielny for the ball during a rare West Ham attack
Ramsey pulled another chance wide when Mathieu Debuchy was better placed outside him and the game changed, two minutes before half-time when Kouyate struck.
Bilic's team dug in to defend their lead, epitomised by James Tomkins who produced a good block to thwart Ozil as Arsenal went in search of instant response.
Zarate fired them two goals ahead and they defended superbly. Sam Allardyce would have been proud. And Wenger's team had no response.
On came Theo Walcott and Sanchez, pressed into action.
Adrian saved from Olivier Giroud and Oxlade-Chamberlain, who ended the game playing at right-back, smashed one into the side-netting, but Arsenal were deservedly beaten.
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Arsenal striker Olivier Giroud slides in to try and score but Spanish goalkeeper Adrian gets down low to block his attempt
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Arsenal boss Arsene Wenger complains about a decision on the touchline during a goalless first half in north London
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West Ham boss Slaven Bilic handed 16-year-old midfielder Reece Oxford his first Premier League start against the Gunners
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West Ham's travelling supporters celebrate after taking the lead at the Emirates in their opening game of the Premier League seaso
Read more: http://www.dailymail.co.uk/sport/football/article-3191132/Arsenal-0-2-West-Ham-Cheikhou-Kouyate-Mauro-Zarate-target-Petr-Cech-endures-afternoon-forget.html#ixzz3iKVvcCbd
