It was, in some respects, not so much a battle of wits but an attempt to scaremonger their way to referendum victory.

Alex Salmond contrasted the 1979 referendum and the ­deindustrialisation that followed with that in 1997 when Scotland, or so he argued, was saved from more of the same but not, of course, all of it, thus the need for independence.

Next was Alistair Darling, whose opening statement ­deliberately conflated the ­independence proposition with Mr Salmond.

"His" currency union plan threatened mortgages and food bills while representing the "real threat" to the NHS (a clever pre-emptive strike).

Both men moved to redress perceived weaknesses in their first joust earlier this month.

Darling mentioned "more powers" following a No vote and sounded like he meant it (unlike last time), while Mr Salmond managed to sound convincing on the currency union (again, unlike last time).

There was a subtle difference, with Mr Salmond seeking "a mandate" to retain sterling rather than it being a fait ­accompli.

Mr Darling asked again about his Plan B; not only did he have a Plan B (although it wasn't directly stated), retorted Salmond, he had three for the price of one.

At no point, however, did it feel as if Darling landed a ­ decisive blow on sterling. Salmond was also effective in returning the former Chancellor's fire on North Sea oil. There were billions, even trillions-worth just waiting to be extracted. Darling cried "but it's volatile!", but again killer blow came there none.

On the NHS the First Minister was less impressive, claiming, incorrectly, to have "operational" but not "financial" control of the health service. Westminster couldn't force him to privatise the Scottish NHS, he warned, but nevertheless he might not have any choice at some unnamed date in the future. It sounded contrived because it was.

The main event was Mr Salmond's performance. Wearing his favourite Saltire tie, he was clearly in the zone, helpfully buoyed up by questions from an audience that could have been handpicked by Yes HQ. In cross-examining Darling he aimed several low blows, on child poverty and his alliance with the Conservatives: "You're in bed with the Tory Party!"

Mr Salmond got shoutier as the debate wore on, with lengthy sections lost amid noise and finger wagging. Undecided voters dearly hoping for more light than heat would have been disappointed. Mr Darling by contrast sounded tired and ­hackneyed ("even your insults are re-treaded" remarked Mr Salmond at one point, and he was right).

On a number of points, however, the First Minister's triumph was one of style over substance: however slick his arguments on currency and health, the underlying arguments remained weak. Yet at the same time Mr Darling often failed to capitalise. If round one belonged to the Better Together leader, then round two undoubtedly went to the First Minister.