Danny Welbeck misses chance to teach Van Gaal a lesson on wasteful night If there was consolation here for Arsenal in a 2-1 home defeat by an impressive, fast-breaking Manchester United, it is in the fact that, this time at least, they did not lose a lead. They should, though, have taken one, after a fast start in which some fine approach play was undone by an untimely lack of cutting edge that Jack Wilshere and Danny Welbeck, in particular, will regret. Arsenal did not lose here because they failed to finish, but rather because they failed to defend. However, it must be said it would have helped, and in more ways than one. Among the many subplots at the Emirates Stadium was a tale of two old striking flames: Robin van Persie returning again to the ground he left to win titles (or a title, as it turned out); and Welbeck, playing for the first time against the club where he spent 14 years, in the colours of the one at which he has been for 12 weeks. Louis van Gaal's assessment of Welbeck's capacities in September had seemed unnecessarily blunt at the time. It would perhaps have been more accurate - sometimes, you sense, Van Gaal just can't be bothered to explain - to have said Welbeck's coltish, scattergun style just did not appeal, whereas, at Arsenal, a little galloping physicality has been a welcome addition. Yet there was an unavoidable sting to Van Gaal's words here, as Arsenal started energetically, created at least four good chances in the opening 15 minutes - two of them for Welbeck - and yet still failed to score the goal that might have been decisive against another brown-paper-and-string United defence. Indeed, in the first half Welbeck delivered a performance that was so instantly recognisable, both in good and bad, that it was almost a little over-egged - a cartoon of Welbeck-shaped centre-forward play. It is, of course, harsh to criticise a striker for failing to score when he hardly missed a presentable chance, but Welbeck worked hard enough here and had enough sight of goal to have repaid Van Gaal in deed on a better day. Instead, he looked at times like the perfect Arsenal player: neat, energetic, oddly blunt, a striker continually preparing to strike. United deserved the win for their incision and the composure of a callow three-man defence, but they might not have been given the chance by a more ruthless opponent. Here, United kicked off in their majorette-style navy away kit with that rejigged three-man defence sitting deep behind a five-man midfield. Paddy McNair, Tyler Blackett and Chris Smalling was a seventh different defensive lineup of the season, an open invitation for Arsenal's attacking front five to gouge a thumb into those apparent points of weakness. Welbeck's first chance came after five minutes, made by some lovely work by Alex Oxlade-Chamberlain cutting in and playing a reverse pass to Welbeck's feet. Eight yards out, his shot was only ever heading one way and it was duly blocked. It was both an assertive start and a moment that seemed to capture the essence of uncut, premier cru Welbeck: the fine movement to find the space; the slight, but telling, lack of razor edge. Moments later, it was almost but not quite again, as Oxlade-Chamberlain dug out a lovely cross from a tiny patch of grass to find Welbeck in the centre. He saw the ball all the way. He set himself. He headed over the bar. After which, Welbeck continued to perform pretty much every other part of the centre-forward job description - the learned disciplines, the add-ons - with some craft. It was his neat one-touch pass that put Wilshere in on goal, only for the midfielder to prod the ball at the excellent David De Gea from almost inside the six-yard box, a slightly surreal loss of bearings at just the wrong moment. At the end of a first half in which Arsenal had had seven shots on target to United's zero, Welbeck was still the more impressive of the two returning strikers. Van Persie did not miss any chances but he also scarcely featured as an animate object before he was substituted. Yet Arsenal really should have scored at least once in that 15-minute spell. Faced with an opponent teetering on the edge of the battlements, they thrust at United not with a rapier edge but with a breadstick. United settled either side of the break, with Marouane Fellaini asserting himself and Ángel Di María sniping in off his flank in that familiar crazed cartoon-mouse style: watching him being chased by Mikel Arteta was an absorbing sight, an oddly moving triumph of hope over logic. The opening goal arrived after 55 minutes, Kieran Gibbs deflecting in Antonio Valencia's shot after some muddled defending. Wayne Rooney's second was a belated moment of striking precision, matched at the death by Olivier Giroud's fine left-footed strike to make it 2-1. Welbeck, for his part, played well and will have better days. Any real surge in his goalscoring returns was always likely to require a period of adjustment, of relearning that central position in a set of new team-mates. But this was still, on balance, a chance missed - in more ways than one.