Reform UK and the Green Party finished second and third respectively, and many suspect they could both be much more competitive this time.
Reform’s leader Nigel Farage was quick to relish what lies ahead.
“This by-election is by no means a certainty for Labour, the left-wing Greens will split their vote, and we will be the challenger. We will give it our all,” he said.
It is far from certain, even in this scenario where Andy Burnham is the Labour candidate, that he makes it back to Westminster.
But it is also true this might be his one chance to return to Westminster, in a seat in his patch, with a vulnerable prime minister and plenty of chat among Labour MPs about who might replace him.
So finally, let’s imagine he is Labour’s candidate and he wins.
It is entirely possible he would do so just as Labour did badly in elections in Scotland and Wales, and the local elections in many parts of England in May.
And so he would arrive on those green benches in the Commons at just the point many Labour folk anticipate the prime minister reaches his stickiest moment yet. Is this the point he is a challenger for the Labour leadership, alongside others?
As I say, this marble run is long and twisting. But it could become the political spectator sport of the spring.