Midway through a hard-fought first half at the Liberty Stadium a rainbow appeared. Not just any rainbow, one of those glorious technicolour efforts which make you feel warm inside.

It actually looked as if one end appeared to finish in the away section where the loyal and vociferous travelling support was located – even if one wag suggested Arsene Wenger wouldn’t spend the crock of gold during this transfer window anyway.

But the colourful apparition only served to momentarily distract eyes from what was a hugely impressive opening 45 minutes in Paul Clement’s tenure as Swansea City head coach.

The question at half-time after Arsenal edged ahead through another important Olivier Giroud goal – making it nine in nine and 11 in total – was whether Swansea could keep up their intensity and knock their more gilded visitors off their stride.

Three second half goals to make it a 4-0 rout proved Clement’s team simply couldn’t sustain their intensity. And we all know teams that lack confidence never get the rub of the green when their luck is out.

But even if two of the goals were fortuitous, it was still an efficient performance from the Gunners as they made it 27 league strikes away from home.

Was it really only four years ago that a buoyant Swans team walked away from Valencia’s imposing Mestalla Stadium with an unlikely win against one of the giants of Spanish football in the Europa League?

If a week is a long time in the game, then four years is an eternity. One thing that doesn’t change is the fact that a team from this proud working-class city always give their London visitors a tough match.

And so it was with the home team, fired up by the arrival of a new manager, the highly regarded Clement – who Arsenal’s upcoming Champions League opponents Bayern Munich agreed to release from his role as Carlo Ancelotti’s number two.

In the years laden with a League Cup triumph and Europeans trips, the Swans were renowned for their work-rate and intensity of their pressing.

However, the instability brought on by a number of changes of management, and a lack of a coherent strategy – on and off the pitch – has led to a far more laissez-faire approach.

It was clear in the early stages that Clement has already convinced his charges of the benefits of hard work in closing down the opposition.

And when the opponents are Arsenal, it tends to lead to a more attacking ethos. If you add good technique and impressive movement to the home side’s armoury, it was no wonder Wenger’s men were under the cosh in the early stages.

But the Gunners knuckled down and ultimately their quality showed. Was it because they realised a defeat, or even a draw in south Wales would have effectively ended their underwhelming argument as title contenders? It was difficult to tell what was more impressive from Arsenal – their refusal to buckle under intense pressure in the first period, or their second half power-play.

The year rolls on, with pivotal moments still to come. The memory of the 4-0 victory at Swansea – as satisfying and easy on the eye as the first half rainbow over the Liberty – will be soon be saved in the file ‘four-goal victories during the 2016/17 season’.

But in terms of continuing to cling to the coat tails of the title challengers its importance cannot be underestimated – even if come May the joy and satisfaction gained from this win may prove as fleeting as that rainbow.

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