Arsenal breathed new life into their chase for the Champions League places, and also erased their horror show in Rennes, with a dominant performance over top4 rivals Manchester United.An early goal from Granit Xhaka and a penalty from Pierre-Emerick Aubameyang was the tip of the iceberg in terms of the match details, but victory was the bottom line and it was the first defeat of Ole Gunnar Solskjaer’s reign.Unai Emery masterminded a consummate display and went with a very bold lineup for the game, with the emphasis on creation rather than containment. This meant another start for Mesut Ozil, his second on the bounce following our defeat in Rennes, and he was part of a 3-4-1-2 formation that was fluid in everything but name. Players floated and contorted their positions in order to give the man on the ball options, and it meant the first half especially was United chasing shadows.Our defence comprised Sokratis, Koscielny and Monreal, with Ainsley Maitland-Niles and Kolasinac performing double duty in attack and covering the flanks. In midfield, Aaron Ramsey was the surprise choice to partner Granit Xhaka, and the Welshman was a true dynamo, putting in a huge number of tackles throughout and also being a nuisance in United’s box.The first half was an exercise in smart possession. While United had chances, Lukaku had an early close range chance that hit the woodwork, it was clear that we were the team with the most initiative. On countless occasions we picked up the second ball before United and we were quick to go on the front foot.The difference between this and other displays though, was we lacked the naivety that sometimes costs us as we pile forward. United were so often pressed into errors, and we made good use of the ball.Our first goal was a perplexing affair. Granit Xhaka took aim from roughly twenty five yards in a central area. His shot swerved early, seemingly wrongfooting David De Gea and the ball ended up in the net. Replays showed that there were no deflections, but the flight of the ball must have deceived him, but it didn’t matter - we had the lead we deserved.We coudn’t rest on our laurels though, and Fred reminded us that as his long range shot dipped over Leno’s outstretched hand and hit the base of the post. That was twice that United had struck the frame of the goal, even if we had been the better side.The first half saw us keep United at arms length, and when we had the ball we used it effectively, no sign of self-capitulation was on the pitch.The first half ended and even though we had put in a cracking performance and had the lead, most of us couldn’t quite enjoy it. We had been burnt by United like this on too many occasions.The second half began and United were starting to creep into the game, and Leno really came into his own with a stupendous stop from Lukaku with his leg, when the Belgian was all alone in the box.It was a vital stop and Leno had rescued us again after his brilliant double save last week. We hadn’t let go of the control though, and we began to turn the screw again, with Maitland-Niles and Kolasinac especially finding joy down the wide areas.Then, after some cagey midfield battling, we had the opening for the second. Lacazette was seemingly bundled over by Fred. Replays showed that the penalty was a soft one, but we have given away so many penalties similar to this - the forearm in the back of Harry Kane last week was eerily similar - so we can’t feel like we hoodwinked the ref.Pierre-Emerick Aubameyang stepped up, and he exorcised his demons with a cool penalty straight down the middle.Lacazette had earned the penalty, and his non-stop running and industry was the impetus behind us giving Chris Smalling and co a hard time at the back.Then, a moment of lunacy from one of our ‘supporters’ as they ran onto the pitch and shoved Smalling. Strangely, this was the second time in a matter of hours that a fan had ran onto the pitch and attacked a player, with a