Scotland's pro-independence leader Alex Salmond easily won a final TV debate on Monday night just over three weeks before a breakaway referendum, but it wasn't clear if this would help him catch up in the polls.

In a bruising debate before the Sep 18 referendum, Salmond relentlessly talked over Alistair Darling, the leader of the anti-independence movement, arguing Scotland would be wealthier, freer and better governed if it went it alone.

With the campaign to break up the United Kingdom and sever Scotland's 307-year union with England trailing in opinion polls by an average of up to 14 percentage points, Salmond's supporters were looking for a game-changing performance after he lost the first such encounter.

Salmond, 59, did much better this time.

In a snap Guardian/ICM poll, 71 percent of over 500 respondents judged that Salmond had won, against 29 percent who said they thought Darling had triumphed.

If Scotland, with its $250-billion economy, 5.2 million people, oil industry, and nuclear submarine base, leaves Britain, with its $2.5 trillion economy and 63 million people, the consequences would be profound.

Britain's three main political parties want it to stay in the union, which includes England, Wales and Northern Ireland.

Professor John Curtice of Strathclyde University, a polling expert, agreed that Salmond had comfortably won the debate. But he questioned whether the nationalist leader's rhetorical victory would translate into a win at the ballot box.

"A debate doesn't necessarily win you votes," said Curtice, adding that the evening had been notable for its lack of proper discussion about wider economic questions.

"My glance at the flash poll is that while Salmond was the obvious winner, it doesn't seem to have moved votes at this stage," he said.

Scotland's press feted Salmond's performance. "Salmond Bounces Back," said the Daily Record, the second best-selling newspaper, while the top selling Sun said Darling, the leader of the "Better Together" campaign, had been "smoked" by Salmond.

Salmond, the leader of the pro-independence Scottish National Party, got more cheers in Glasgow, Scotland's biggest city, than Darling, 60, who attracted the odd groan from the audience. But he didn't land a knockout blow.

Instead, over the course of a scrappy hour-and-a-half, he repeatedly interrupted Darling and asked him the same questions again and again, a tactic that unsettled the former British finance minister who at times struggled to find a riposte.

"The eyes of the world are indeed focused on Scotland," Salmond told the audience in an emotional opening statement, urging Scots to vote for full independence. "This is our time, our moment. Let us do it now."

Scotland's health service would be better off under independence, he argued, questioning whether the British government would give Scotland more devolved powers if independence was rejected.

Scotland already has its own parliament with control over policy areas such as education and health.