Dressed in a strict black suit that contrasted with her usual pale colours, she even suggested that Mr Sarkozy “do his homework” when the pair clashed over nuclear reactors.
Ms Royal and Mr Sarkozy sought to prove that each had the formula for pulling France out of its relative economic stagnation and sense of moral crisis, but the Socialist dwelt on her empathy for the people while Mr Sarkozy talked figures and policies.
“I want to be the president who creates a France where aggression and violence is receding, a France that will win the battle against unemployment,” Ms Royal said.
“You are in part responsible for the situation in which France finds itself,” she told Mr Sarkozy.
She accused Mr Sarkozy’s Government, in which he served as Interior and Finance minister, of failing to tackle unemployment and street crime. “Madame, do you want me to complete a sentence?” he asked at one moment, tripping over his words.
Ms Royal attacked him over his plans for heavy cuts in the civil service and cited the case of a policewoman who was raped last month as she returned from work at night.
“Under my presidency every woman police officer will be accompanied to her home after work,” Ms Royal said. She scored points when Mr Sarkozy denounced the 35-hour maximum working week, introduced in 1999 by the last Socialist Government .
“The 35-hour week was a complete catastrophe for the French economy,” Mr Sarkozy said. Ms Royal shot back: “Then why did you not scrap the law if it was such a disaster?”
Mr Sarkozy sought to depict Ms Royal as an old-school tax-and-spend Socialist, and gained the upper hand when he pressed Ms Royal on her plans for raising the incomes of the poor and pensioners with new taxes on business. “Give me figures,” Mr Sarkozy said.
She replied: “My tax will be at the level necessary for social justice.” He came back: “That’s a stunning piece of detail. Can’t you give us a figure?” Ms Royal replied: “No, I can’t.”
“I see,” said Mr Sarkozy, who began his career as a trial lawyer.
No winner or loser emerged at the end of nearly two hours, but the consensus was that she had performed better than expected against an opponent with superior debating skills.
“Ségolène Royal pulled it off well,” Stephane Foukes, a director of the Euro RSCG agency, said. “Sarkozy was no doubt guided by the fear of getting carried away.”
But commentators agreed that there was no knockout punch on either side.
Sarko and Ségo head to head in a public debate for two and a half hours, watched by 20 million viewers, was a riveting piece of political theatre. And the flash point which encapsulated the entire debate was a fierce disagreement about Nicolas Sarkozy's policy on special needs education. But what made the exchange so intriguing was its blatant display of Gallic machismo: Sarkozy used, several times, the classic patronising put-down routinely fired at any woman when she is forceful: "Calm down! Calm down!"
It's a reference back to an era when women who had opinions or were assertive with their views were dismissed as "irrational" or "hysterical". A woman was expected to be seen not heard. Now, the phrase is a clever tactic to use in a heated discussion with a woman (men very rarely say it to each other) to infuriate and disorientate - and thus throw a woman off her argument. "Calm down" is a very effective wind up.
The woman is then not just defending her position in the argument, she is also having to defend her emotional stability. It's just one of many ways in which women get outmanoeuvred in debate, not because of the weakness of their argument, but because of the techniques of claiming and asserting authority are so culturally unfamiliar to women; they are bred into men from an early age, they are rooted out of women from an early age.