Goals from Granit Xhaka and Pierre-Emerick Aubameyang guided us to an impressive 2-0 win over Manchester United on Sunday, ending their 12-game unbeaten streak in the Premier League.
But what did we learn? Read on to find out...
For only the second time this calendar year, Emery selected Aubameyang, Lacazette and Ozil in the starting XI.
It was the 11th time the trio had lined up together from the start, and we remain unbeaten in those matches. Our record in such games is now P11 W7 D4 L0.
Earlier this season those three were often selected with Aubameyang on the left and Lacazette up front on his own. This time though the two strikers operated as a more orthodox front two, with Ozil buzzing around just behind them.
And it worked. Ozil created four goalscoring chances (more than any other player on the pitch), Lacazette added his seventh Premier League assist of the season, while Aubameyang was back on the scoresheet, for his 20th goal across all competitions this season.
The three were too hot to handle at times, and might just hold the key in the season's run-in. The big frustration is that Emery will be forced to break up the trio for Thursday's big game against Rennes, as Lacazette completes his European suspension.
It wasn't immediately obvious who would take the ball when Jon Moss pointed to the penalty spot after Fred's foul on Alexandre Lacazette.
Just eight days ago against Tottenham Aubameyang saw his injury-time spot kick saved, wasting the chance to go within a point of our local rivals.
And with Lacazette on the pitch here, it would have been no surprise to see the Frenchman step up himself once the penalty was awarded.
But instead he handed the ball to his strike partner, along with several morale-boosting words of encouragement, and then raced over to his team-mate once the ball hit the back of the net.
It was a big moment, not just in the context of the game, but to give our striker a huge confidence boost as the season reaches its business end.
Not that he looked low on confidence when stroking the ball calmly into the middle of the goal, sending de Gea the wrong way.
LENO'S BIG SAVES
Bernd Leno richly deserved his clean sheet. For the second weekend in a row our goalkeeper came up with a huge save at a crucial moment.
United had ended the first half strongly, and outlined their attacking intentions at the start of the second half as well. So there's no doubt the momentum would have shifted had Romelu Lukaku converted his chance on 50 minutes.
Marcus Rashford found the striker unmarked in the area but Leno immediately closed him down, racing off his line to deny the in-form Belgian with an outstretched leg.
It was one of four saves the goalkeeper made, and although it might not get the same plaudits as his remarkable stop from Moussa Sissoko's shot at Wembley last weekend, but it was no less important.
This was the first away game United had failed to win since Ole Gunnar Solskjaer took over at boss, and indeed the first time they had ever been behind on the road.
THE MIDFIELD DOUBLE-ACT
With Mesut Ozil operating in the number 10 role, Aaron Ramsey was given the task of patrolling the central midfield alongside Granit Xhaka, and it was a job he revelled in.
Ramsey won a game-high eight tackles, one of which near his own corner flag led to a superb lung-busting run into enemy territory, only ended by the offside flag against Sead Kolasinac.
As for Xhaka, he had more touches than any other player on the pitch (64) one of which was the all-important opening goal.
"He must be Brazilian" was how Ole Gunar Solskjaer explained the incredible swerve on his first-half shot which deceived David de Gea and found the net from 25 yards.
It was his 11th goal for the Gunners, all but four of which have been scored from outside of the area.
The work that he and Ramsey got through in the middle of the pitch meant that Lucas Torreira's enforced absence due to suspension did not adversely affect the team.
This was our ninth consecutive home win in the Premier League, and we now have the second-best home record in the league.
Since the opening day defeat to Manchester City, we are unbeaten at the Emirates in the Premier League, taking 41 points out of 45 since then.
We have three home games remaining in the Premier League, compared to five away, but before any of those we have a huge match on Thursday night in the Europa League.
We need to win by at least two goals against Rennes, but the encouragement should come from the fact that today's result was the 14th time we have won by at least two goals at home already this season.
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