Arsenal 1 Southampton 0

Arsenal have their momentum. This had been billed as the night when they would build upon the encouraging wins over Borussia Dortmund and West Bromwich Albion, in which they had kept clean sheets, and for so long it had looked as though they would get only one part of the equation right.

Southampton were comfortably the better team for 70 minutes and the Emirates Stadium crowd bubbled with frustration. Too much of Arsenal’s passing had been off-kilter. But football can be the cruellest of sports and Southampton had plenty of time to reflect on that on their way back to the south coast.

The game swung upon the introduction of Olivier Giroud who was too powerful for the Southampton defence to handle. But Southampton's resistance was truly broken when they were reduced to 10 men. Toby Alderweireld felt a muscle twang on 84 minutes and, with Ronald Koeman having used his three substitutes, the visitors had to try and cling on without their full complement.

They could not. Fraser Forster made a stunning one-handed save to keep out Giroud's header but when Aaron Ramsey recycled a move on the right, after loud appeals for handball against José Fonte were turned down, there was Alexis Sánchez to sweep home from close range. It was yet another decisive contribution from the Chilean. Southampton were crushed.

They had won here in September in the Capital One Cup and they arrived at the Emirates Stadium with their status as the season’s surprise package intact. Mikel Arteta, the injured Arsenal captain, referred to them as such in his programme notes and Wenger had said the same thing in his pre-match press conference.

The visitors were smarting from their 3-0 home loss to Manchester City on Sunday and the accusation that their fine start has owed plenty to a kind fixture list. When they have played the so-called big clubs, the critics had noted, they had lost. City's victory over them followed those of Liverpool and Tottenham Hotspur.

But nobody can dispute the easy rhythm of Southampton’s passing game and it was in evidence at the outset as they settled extremely smoothly. There is a balance to Koeman’s selection and that priceless quality of options for the player in possession.

They might have led when Graziano Pellè, whose frame belies the softness of his touch, turned to beat Aaron Ramsey and chipped neatly towards Steven Davis who headed back towards him. Pellè was in but with Emiliano Martínez off his line smartly, he shot wildly.

The onus was on Arsenal to impose themselves in an attacking sense and they laboured in the first half although they almost drew first blood following a lovely interchange between Sánchez and Santi Cazorla in the eighth minute. Cazorla's through-ball was well weighted but Danny Welbeck who started up front got the left-footed finish all wrong.

Morgan Schneiderlin, the midfielder who has interested Arsenal, missed out through injury and Jack Cork had returned pretty seamlessly in his stead. Cork is one of those extremely unsung players. But his evening was cut short after he was caught by a late Ramsey tackle. He attempted to play on but he was forced off just before the half-hour.

As he had done against City, after Schneiderlin went off, Koeman introduced Maya Yoshida in central defence and pushed Alderweireld into midfield. City took advantage in the middle of the field and the question was: could Arsenal?

Arsenal’s best moment of the first half followed Cazorla’s whipped free-kick from the left in injury time which Welbeck glanced towards goal. Forster distinguished himself with a reflex tip over the crossbar.

Alex Oxlade-Chamberlain flickered against his former club while Sánchez was all spins and bursts, trying to make something happen. But the sense at the interval was one of Arsenal’s glass being half-empty. Forster had saved from Oxlade-Chamberlain but the home crowd could also grumble at a couple of loose back-passes towards Martínez.

Arsenal are hardly known as hatchet-men but, after Ramsey’s lunge at Cork, Cazorla was guilty of leaving his foot in on Dusan Tadic early in the second half. Tadic howled as he went down, clutching his foot and it was one of those that looked worse with each TV replay. Tadic came off moments later although he seemed to be moving without discomfort.

Southampton began the second half with the same fluency and they were left to curse when, after a slick break from the edge of their own area involving Pellè, Shane Long picked the wrong option and chose to shot. Pellè had looked to be clear in the middle for the cross. Moments earlier, Laurent Koscielny had blocked from Pellè.Wenger had to act and he gave the home crowd the player that they had been calling for in Giroud. The decision to remove Oxlade-Chamberlain, though, was booed. The young winger spun on his heels in anguish.

Arsenal crackled to life. With virtually his first touch, the France centre-forward clubbed a fierce effort from a tight angle which Forster beat clear while, on 70 minutes, Giroud’s flick from Sánchez’s pass was made to measure for Welbeck. He shot only for Forster to save. Southampton’s luck was out when Alderweireld signalled that he could not continue. How Arsenal made him and his team pay.

(Guardian Service)