He has not been showered with the praise so often lavished on Mauricio Pochettino at Tottenham and has escaped the scrutiny that has weighed down heavily on Chelsea's Maurizio Sarri. As for Jose Mourinho and Ole Gunnar Solskjaer at Manchester United, Emery's ups and downs at the Emirates have been drowned out by the noise around the two managers employed at Old Trafford this season.

But Arsenal's 2-0 defeat of Solskjaer's United at the Emirates Stadium saw Emery give a timely reminder of his credentials and answer more than a few questions. This was a game that Arsenal needed to win, primarily for their ambition to finish in Premier League's Champions League qualification places, but also because they had to bounce back from Thursday's 3-1 Europa League last-16, first-leg defeat against Rennes in France.

With the return fixture looming against the Ligue 1 outfit later this week, the Gunners' season was threatening to hinge on the outcome of two big games. Defeat in the first one, against a United side buoyed by their remarkable Champions League win against Paris Saint-Germain, would have been a damaging setback to Arsenal's top-four hopes, but Emery chose to be bold.

Some might even argue he was reckless to select an all-out attacking lineup against opponents that had not been beaten in the league since Solskjaer replaced Mourinho in mid-December. It looked as if Emery was about to repeat the mistakes repeatedly made by Wenger against the top teams, by overloading in the attacking half of the pitch and hoping for the best at the back.

Unai Emery gambled with his inclusion of Mesut Ozil and others, but Arsenal emerged with a vital win. Getty

But he nevertheless included Aaron Ramsey, Alexandre Lacazette, Pierre-Emerick Aubameyang and Mesut Ozil in his XI, ahead of Granit Xhaka in midfield and a back three -- Laurent Koscielny, Sokratis Papastathopoulos and Nacho Monreal -- that was trusted to stifle Marcus Rashford and Romelu Lukaku.

Albeit thanks in no small part to some bad finishing by United, the home side's approach worked. Emery has had three-quarters of a season to work with his players on the training pitch at Arsenal's London Colney base, and the defensive drills have clearly had a positive effect; his side looked well-organised and determined against United and were prepared to throw their bodies in the way when it mattered.

That may be a pre-requirement of any footballer, but for too long under Wenger, defending appeared to be something that only the other team did. Emery has sorted that problem out, and as a result, Arsenal are a more obdurate proposition than in the past; their spirit was a big plus in the manager's eyes.

"Being competitive like today for 90 minutes can give us a stronger mentality," Emery said after the game. "They [United] were in a good moment after one result against PSG, but we had a big performance and we are in a good moment in the Premier League. To take three points and get a good position for our target is very good, and I'm happy for the players."

In the closing moments, Arsenal supporters sang, "Tottenham Hotspur, we're coming for you!" as they celebrated a win that moved them within one point of their third-placed neighbours. Defeat at Southampton on Saturday -- their third in four league games -- has dragged Pochettino's side back into the fight for the top four; Spurs, Arsenal, United and Chelsea will fight it out for the final two Champions League spots.

Four points separate Spurs in third and Chelsea, who are sixth with a game in hand. Arsenal have played all of their fixtures against big-six rivals -- this win added to others at home vs. Tottenham and Chelsea -- and so have a favourable run-in. Spurs, meanwhile, have still to visit Liverpool and Manchester City, as well as hit the ground running at their new stadium when they finally move in next month.

United must host City and Chelsea at Old Trafford and negotiate a difficult trip to seventh-placed Wolves, who earned a 1-1 draw at Stamford Bridge earlier on Sunday. As for Chelsea, they face a trip to Anfield in addition to that game at United and, like Arsenal, must juggle league games with Europa League commitments.

Solskjaer was correct when he admitted after Sunday's game that the race "is going to go down to the wire," but by virtue of this win, Arsenal are firmly in control of their own destiny. For that, Emery deserves credit; fortune favoured the brave on this occasion, and it might propel his side all the way into the Champions League next season.