Until Wednesday there was a clear consensus among observers at Holyrood that Labour were heading for victory in May.
Alex Salmond may have pulled a rabbit out of the hat in 2007 but the widely held view was repeating the trick with a much less favourable prevailing wind would be beyond even him.
Without wanting to overstate the case, the latest Ipsos MORI poll changed all that.
Don’t get me wrong, every election has the odd rogue survey and one swallow does not make a spring but the Nats will have taken heart at such a dramatic swing in their favour.
On Wednesday sources in the SNP were honest enough to express some surprise at the poll’s results: they thought the election campaign was closer than many were making out but did not necessarily expect to be in front.
So what could have caused the change? Well, for a start, there has been a sense in recent weeks that Labour has been a little too sure of its victory and acting like a government-in-waiting.
The decision to vote against the Budget despite the SNP ceding to a host of Labour demands on issues like modern apprenticeships, for example, is said to have even upset some of their own MSPs.
Meanwhile, the rest of their campaign to date has largely been characterised by a feeling they did not want to upset the apple cart. They will need to outline their own distinct vision for Scotland more clearly in the coming weeks.
Then there is the issue of leader. Alex Salmond undoubtedly enjoys greater personal popularity and a higher profile than Iain Gray but how much difference will that really make?
It is worth remembering that even at the height of Salmond’s popularity in 2007, and with a detested Labour government in place at Westminster, the Nats could only manage a one-seat victory.
Until May 5 nobody will know if the SNP can secure a second term but this poll has achieved one thing the next 11 weeks just got a lot more interesting.