Manchester United picked up their first away win of the season with a 2-1 victory over Arsenal at the Emirates.

After a cagey first period, Kieran Gibbs turned Antonio Valencia’s sharply struck cross into his own net just after half time to give United something to hang onto. A solid and gritty defensive performance laid the foundations for Wayne Rooney to run through unchallenged and make it two from Angel Di Maria’s pass, before substitute Olivier Giroud scored a late consolation for the Gunners.

Despite the stats being completely in Arsenal’s favour, poor finishing meant United were able to move into the top four of the Premier League. After a shaky start to the season, the Red Devils have managed to string a couple of wins together and with two home games to follow, against Hull and Stoke City, now is the time to look above at Manchester City and Southampton rather than the mid-table scrap below United.

Here are five key thoughts from the crucial victory this weekend.

1) United reap rewards from Van Gaal’s latest risk

Louis Van Gaal is not known for his conservatism. In his latest controversial tactical switch, he reverted to a back three despite only having one senior centre-back fit. Phil Jones, Jonny Evans and Marcos Rojo were once again missing as Tyler Blackett and Paddy McNair filled in next to Chris Smalling to form a make-shift United backline. Luke Shaw and Valencia were the full-backs whilst further forward, Di Maria played alongside Robin Van Persie with Wayne Rooney in behind.

After a disappointing first half an hour in which Arsenal completely dominated, United grew into the game as Smalling began to relish his role in the heart of the back three. Following Shaw’s injury, Ashley Young made his return to the side and impressed in his role as left-wing back. It may have taken a bit of luck to break the deadlock but afterwards, United were tremendous defensively, counter-attacked superbly and were able to reap the rewards, meaning Van Gaal’s risk eventually paid off.

2) McNair, Blackett and Wilson prove that United are still focusing on youth

After Danny Welbeck’s deadline day departure, United’s youth system was written off by many. Following a summer spending spree which saw £150million splashed on new players, apparently United’s focus had moved away from producing their own talent. How wrong these critics were. Although injuries have made it a necessity at times, McNair and Blackett have both been given plenty of starts this season whilst James Wilson has also appeared off the bench several times and impressed.

United have a 100% win record when McNair has started this season, with many believing he should keep his place in the side once Jones, Evans and Rojo return. His composure and positioning is excellent for a defender so young and at least the Northern Irishman appears to be able to keep himself fit for a prolonged run in the side. If Blackett can cut out some of the longer passes he attempts, he also has a shot at becoming a regular in United’s first team whilst Wilson is held in extremely high regard at United and could easily start next Saturday with Van Persie’s poor form in mind.

3) Pressure building on Van Persie

I’m becoming quite bored of speaking about Van Persie’s sudden decline but his performance at the Emirates against his former club cannot be ignored. In the first half, even David De Gea completed more passes than the Dutchman, who only managed 12 touches of the ball in total, including three when he took corners, before he was hauled off in the second half.

It was the latest in a long line of frustrating and laboured displays from Van Persie this season and it is not good enough. With Wilson showing he is more than ready to start in his recent cameo appearances and Radamel Falcao’s return looming large, it is surely the right time to give Van Persie a rest and make him realise that nobody’s place in the side is indispensable.

4) Rooney is growing into role as captain

Rooney got plenty of stick when he was given both the United and England captaincy earlier this season but he has shown recently that he is maturing into the role. After his stupid red card against West Ham, Rooney has been fantastic since returning from suspension and shown that he is more than capable of leading this United side up the table.

His winning goal against Arsenal made it four goals in a week for the United skipper after his three goals on international duty with England. He is hitting form at exactly the right time as United look to take advantage of their faltering rivals in the Premier League. Rooney is proving that his problems at the club appear to be a thing of the past and that he was the right man to take the captains armband.

5) De Gea continues to prove that he is one of the very best

Some of Arsenal’s attempts on goal may have been extremely tame but David De Gea proved once again that he is developing into one of the best keepers in the game. He made a string of saves on Saturday to keep the score down, especially in the first half. His terrific display gave United a platform to go and win the game in the second half as the Gunners pushed men forward.

The latest De Gea master-class is nothing new. He has been producing top class performances for over a year now but he has started to add consistency to his game. De Gea’s work in the gym is also beginning to pay dividends as you can tell that he is much more confident in claiming crosses than he was when he first moved to England. United need to tie him down to a new long-term contract before Real Madrid come calling next summer as it will be very tricky to find a keeper in the class of De Gea.