Will this victory revitalise Yes camp?
While Alex Salmond is broadly judged to have won the debate, it remains to be seen whether he has done enough to "inject some degree of momentum" into the Yes campaign, and persuade voters to back independence, according to politics expert Professor John Curtice.
Speaking on post-debate analysis on BBC Scotland, he said: "This was a much better evening for Mr Salmond than the first debate a few weeks ago.
"I certainly think there were a couple of points in the debate where he clearly had Mr Darling in trouble."
Prof Curtice, of Strathclyde University, said these areas included the notion that if people say Yes, they are also voting for Scotland to keep the pound, and the issue of more powers in event of a No vote.
"Now that said, it is not the case that Mr Darling did not have his powerful arguments," he added.
Mr Darling, he said, had been "keen to reinforce an impression we already know exists among voters, and that is that the prospect of independence looks rather riskier than staying in the union".
Prof Curtice added: "I think we can anticipate that certainly most commentators will reckon that probably Mr Salmond was the winner tonight, but whether he has done enough to move the numbers I think may be another question.
"What was remarkable about tonight's debate was how little time was spent on the issues we know are likely to switch voters minds and that is what are the prospects for Scotland's economy, either in independence or in the union."
"The question that remains to be seen ... is whether Mr Salmond has done enough to inject some degree of momentum into the Yes campaign. What I think it certainly will do, it will raise the hearts of Yes supporters."