Mesut Ozil was Arsenal's hero grabbing the winner at Middlesbrough to keep his team in the hunt for the Champions League and perhaps his manager in a job.

Here are five things we learned at the Riverside:

1. Three-sy does it

Arsene Wenger plumped for a back three for the first time since 1997 when a certain Tony Adams – whatever happened to him? – was patrolling the defence. While Rob Holding may never be mistaken for that particular club legend the change in shape did seem to suit the Gunners with the whole side looking a more solid, well put together outfit from the shoddy mess we saw a week ago at Crystal Palace. Now, Grant Leadbitter is no Wilf Zaha, granted, and Negredo stole in behind them far too easily, but it's baby steps. This was better from Arsenal even if just a little.

Middlesbrough vs Arsenal player ratings Show all 22 1 /22 Middlesbrough vs Arsenal player ratings Middlesbrough vs Arsenal player ratings Brad Guzan – 6 out of 10 Dealt with most that Arsenal threw at him but should have done much better with Sanchez’s free-kick. Getty Middlesbrough vs Arsenal player ratings Antonio Barragán - 6 Solid if unspectacular night on the right side of defence. Getty Middlesbrough vs Arsenal player ratings Ben Gibson – 7 Marshalled Giroud well and handled the Frenchman’s physicality without too much trouble. Getty Middlesbrough vs Arsenal player ratings Daniel Ayala -7 Capable in defence but should’ve done better with second-half header. Getty Middlesbrough vs Arsenal player ratings George Friend - 6 Exposed by Oxlade-Chamberlain at times but solid enough in relief of the injured Fabio. Getty Middlesbrough vs Arsenal player ratings Adam Clayton – 5 Typically workmanlike in defence but a poor challenge cost Boro dearly from the resulting Sanchez free-kick. Getty Middlesbrough vs Arsenal player ratings Marten de Roon – 6 Failed to really assert himself on the game. Getty Middlesbrough vs Arsenal player ratings Grant Leadbitter – 6 Ugly first-half tackle on Ozil could’ve earned him more than just a yellow but showed well in attack. Getty Middlesbrough vs Arsenal player ratings Stewart Downing - 7 Rolled back the years with an inch-perfect ball for Negredo’s goal. Getty Middlesbrough vs Arsenal player ratings Alvaro Negredo – 7 Quiet night as the home side’s focal point but took his goal with a poacher’s instinct. Getty Middlesbrough vs Arsenal player ratings Gaston Ramírez – 7 Boro’s brightest attacking threat and looked the home side’s most likely to break the Gunners back line down. Getty Middlesbrough vs Arsenal player ratings Petr Cech - 6 Not tested a great deal and deserved better from his defence for Negredo’s goal. Getty Middlesbrough vs Arsenal player ratings Gabriel – 6 Always on the edge of an utter calamity the Brazilian managed to avoid any tonight and looked better in a three. Getty Middlesbrough vs Arsenal player ratings Laurent Koscielny – 7 Arsenal’s best defender but will have wanted to do better with Negredo’s goal. Getty Middlesbrough vs Arsenal player ratings Rob Holding – 7 Definitely a player for the future if not right now. Getty Middlesbrough vs Arsenal player ratings Alex Oxlade-Chamberlain – 7 Pushed on well down the right flank and offered positional discipline going the other way too. Getty Middlesbrough vs Arsenal player ratings Aaron Ramsey – 7 Neat and tidy as ever and added a dash of quality with a deliciously composed chested knock down for Ozil’s goal. Getty Middlesbrough vs Arsenal player ratings Granit Xhaka – 7 Doesn’t know whether he’s coming or going but plenty of energy if not so much discipline from the Swiss. Getty Middlesbrough vs Arsenal player ratings Nacho Monreal – 7 Added some good balance on the left and thrived with the added attacking responsibility. Still a little clumsy in the defence. Getty Middlesbrough vs Arsenal player ratings Mesut Özil – 7 Took his goal with the composure required and added the class when the Gunners needed it most. Getty Middlesbrough vs Arsenal player ratings Alexis Sánchez – 8 Not one of the Chilean’s best games yet was still the outstanding performer scoring one and creating another. Getty Middlesbrough vs Arsenal player ratings Olivier Giroud – 7 Didn’t threaten as much as he would’ve liked but added the focal point that Arsenal lack with Sanchez up top. Getty

2. French revolution

Oh how Arsenal have missed their talismanic centre-back. Laurent Koscielny has been absent since the second half against Manchester City and it has showed. He has a mistake in him, as most centre-backs do and as he showed for Negredo’s goal, but his presence appears to calm everyone around him and did so at the Riverside where Holding, a surprise starter, dealt with everything thrown at him with relative ease.

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3. It's not all bad for Boro

It remains early days for Steve Agnew’s Boro and it may well be too little too late but they do look an altogether better team with the new man in charge. They can be got at more now – as Arsenal showed – but they also offer a lot more going the other way, far more than under the stewardship of Aitor Karanka. The future may be Championship-shaped, but it’s by no means all doom and gloom.

4. Sanchez the saviour

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In their current guise Arsenal aren’t a good enough football team to get over the line despite playing badly. But in Sanchez they have a match-winner who can get them out of jail time and again. The Gunners shaded the first period, perhaps, but went into the break ahead thanks to the sole slice of quality shown in an otherwise bang average affair. That, in essence, is what Sanchez is in this team – the extraordinary buried amongst the ordinary. Lord knows what they will do without him.

5. Ozil to the rescue

Ozil celebrates his winning goal against Middlesbrough (Getty) (Getty)