With the novelty of the clash between the three would-be prime ministers beginning to wear thin, the debate exposed not only the Prime Minister to increased scrutiny, but also Conservative leader David Cameron and Nick Clegg, for the Liberal Democrats. At the heart of the exchanges was Mr Cameron's attack on Mr Brown, who again forced himself to apologise – albeit obliquely – for his injudicious remarks on Wednesday about pensioner Gillian Duffy, who he had described as a "bigoted woman".
Responding to Mr Brown's claim that the Conservatives would take Britain back to the 1930s, the Tory leader tellingly accused Mr Brown of being desperate, an attack that will resonate with many voters.
Although Mr Brown appeared nervous, the other leaders did not have it all their own way, with Mr Cameron failing to make as much as he might of Labour's dismal economic record.
Mr Clegg, the fresh-faced success of the first debate tried too many times to present himself as not like the others, claiming he was not political point-scoring when he was doing just that.
For all the faults of the restricted format, at the end of this process, the voters have seen more of their potential prime minister than ever before and they now have to make a judgment.
In last night's final round of a marathon bout, the battered old bruiser Brown tried to swing his clunking fist but his hay-makers were drained of power. Next Thursday, the public can call a halt to save further injury.