Suddenly, in the space of an hour, and after talk of the Labour leadership contest becoming a two-horse race between Sir Keir Starmer and Rebecca Long-Bailey, one outsider has fallen at the second hurdle and another is coming up on the rails.
Jess Phillips, lacking support and admitting she performed badly in the only public hustings so far, has pulled up and withdrawn from the race.
But Lisa Nandy, everyone’s third choice, is suddenly emerging as a real challenger and a threat to the top two.
The withdrawal of Ms Phillips was predictable, but will still be a bitter disappointment to her supporters on the anti-Corbyn wing of the party.
For Ms Nandy, the GMB’s nomination was always going to be crucial if she was to kick-start her campaign.
Both of the dramatic developments in this so far low-key campaign could together have the same effect.
Ms Phillips’ withdrawal could provide a further boost to the Nandy campaign if many of her supporters or would-be supporters switch their support to the Wigan MP.
Ms Nandy impressed Labour MPs at the hustings in parliament last week. She then performed well in a TV interview with tough interrogator Andrew Neil and she obviously impressed the 60-strong executive of the GMB.
The union’s pragmatic and down-to-earth general secretary, Tim Roache, described Ms Nandy as “a breath of fresh air”.
And there’s no doubt her GMB nomination – which could now be the first of many from unions – will force Sir Keir and Ms Long-Bailey to raise their game.
Ms Nandy has been MP for Wigan since 2010 and backed Andy Burnham for Labour leader in 2015 and Jeremy Corbyn’s challenger Owen Smith in 2016.
She quit the shadow cabinet and as a result has never been trusted by Mr Corbyn or his inner circle.
During the parliamentary battles over Brexit last year, she was a powerful voice for Leave-voting northern towns.
Her warnings about Labour’s support for a second referendum proved correct when dozens of seats in the party’s heartlands fell to Boris Johnson’s Tories in the general election.
The GMB’s endorsement means she is now virtually certain of getting on to the ballot paper when party members begin voting on February 21.
And the GMB has ensured that what looked like a two-horse race just hours earlier now looks more like a three-horse race.
While Sir Keir has picked up the support of Unison and USDAW, Ms Nandy already had the NUM – a tiny shell of a union these days – in the bag.
Ms Long-Bailey looks certain to pick up Unite and the CWU. Candidates need at least three unions or 33 local parties by 14 February.
While the top three look like hoovering up union support, it means the fourth candidate in the race, Emily Thornberry, will probably have to rely on support from constituency parties.
But she might benefit from some local parties lending her their support so she gets on the ballot paper.
Supporters of Ms Phillips claim she would have been a breath of fresh air in the Labour leadership contest. She was always the outsider, both in her chances of victory – zero – and in her approach to the campaign – taking on the party establishment.
Since her election to parliament in 2015, when she defeated another maverick MP, the Lib Dem John Hemming, she has been outspoken, controversial and – her supporters would claim – honest and courageous.
But her critics would claim that she is a self-publicist who was out of her depth in a leadership contest, lacking the discipline to mount a serious challenge. And her detractors will no doubt now be crowing: “The ego has landed.”
At the outset of the campaign, she attracted enough support from Labour MPs to clear the first hurdle, securing the required nominations from a minimum of 22 MPs or MEPs, relatively painlessly. Unlike Emily Thornberry, for example, who had to endure a last-minute scramble.
But her backers could be described – unkindly, to be fair – as the Blairite rump of the parliamentary Labour Party. They included some of Mr Corbyn’s harshest critics, such as Neil Coyle, Margaret Hodge, Liz Kendall, Siobhan McDonagh, Pat McFadden, Ian Murray and Wes Streeting.
Her lack of discipline showed early in the campaign when, in a TV interview in the New Year, she suggested she could campaign to re-join the EU if she became leader, a move seen as a gaffe given Labour’s Brexit battering in last month’s general election.
And then came the first Labour Party hustings, in Liverpool last Saturday.
The consensus was that Ms Phillips performed badly. But she made matters worse by admitting as much and hinting she might be about to pull out of the race. Honesty? Certainly. But it was probably deeply damaging.
“I hated the first hustings on Saturday,” she wrote in a brutally self-critical article for The Guardian. “I was awful. The likelihood that anyone but Keir Starmer or Rebecca Long-Bailey is going to win is, well, pretty low.
“The likelihood of someone like me, who speaks like I do and says the things I say, ever being elected to be a party leader is slim.
And in what now looks like a signal that she was about to pull out, she added: “I might not look the most like a prime minister in this race. I cannot win that war so I am going to stop fighting it… I probably won’t win.”
Her analysis about the top two candidates at the time was almost certainly correct.
MPs were talking about a “Starmer steamroller”. And Rebecca Long-Bailey will have the massed ranks of the grassroots group Momentum campaigning for her.
Jess Phillips picked up no unions or constituency parties in her short time in the leadership race and it’s difficult to see where that support might have come from even if she had remained in the contest for longer.
So there was a certain inevitably about her withdrawal.
Her supporters will say it has deprived the contest of an authentic, refreshing and anti-establishment voice. Her rivals will naturally be wondering where her support – and that of her Blairite rump backers – will go now.
If it goes to Lisa Nandy, these two dramatic and highly significant events within an hour of each other could prove to be a turning point in the campaign.