In a forceful display in the Place de la Concorde before a sea of tricolour banners, Sarkozy rallied his UMP party's right-wing faithful with an appeal to an "Eternal France" embodied by Moliere, Napoleon and Charles de Gaulle.
Further east, by the Chateau de Vincennes, Hollande told a similarly huge but visibly more diverse crowd that it was time for a change after five years of injustice and austerity at the hands of Sarkozy and financial markets.
Both events matched the campaigns' hopes and set the stage for a week of campaigning ahead of the April 22 first-round vote, which is expected to see the pair chosen as frontrunners to proceed to a May 6 run-off.
"You are France!" Sarkozy declared to his supporters, targeting right-wing traditionalists with attacks on multiculturalism, teaching unions, affirmative action and Europe's open borders, while defending families and hard work.
"I will never accept an egalitarian, levelled-out France that turns its back on talent because it fears it," he declared, to wild cheers.
"We will never accept multiculturalism. We will never let the founding institutions of the republic be destroyed," he said, vowing again to hold referendums if his planned reforms are blocked by the political system.
He promised a debate on allowing the European Central Bank to support growth, an idea that puts him on collision course with Germany.
"This is a question that we cannot avoid. Because if Europe doesn't want to lose its footing in the world economy, it absolutely needs growth," he said.
And he repeated his demands for tighter border controls and EU trade protectionism.
"What has happened in the past four years are warning signs that the world must recognize. I tell you gravely: What is at stake is no more nor less than the survival of a form of civilisation – ours," he said.
"Take your identity in your hands! Stand tall! Speak out! Declare strongly what you want for your country! Have no fear," he declared.
Sarkozy's display oozed a confidence not supported by recent opinion polls, all of which forecast a comfortable victory for Hollande in the second round, and the Socialist was no less forceful in his own address.
Declaring himself the saviour of the "French dream" he vowed to defend France against global capital markets and renegotiate the European fiscal compact to replace its austerity measures with a plan for growth.
"I will be the president of a republic much stronger than the markets, a France stronger than finance," he said. "I will be a president of justice.
Before taking any decision, I will ask myself: 'Is this fair?'."
"We have waited too long – 10 years in opposition! We have a duty to win. On April 22 give me the force to lead you to victory on May 6. Next Sunday is our victory, all of us together," he declared.
Place de la Concorde, just across the River Seine from the National Assembly and lying between the Champs Elysees and the Louvre, was the scene of Sarkozy's triumphant victory rally in 2007.
UMP leader Jean-Francois Cope claimed 100,000 had come to cheer Sarkozy, but observers thought this exaggerated.
The Socialists also claimed 100,000, and the rival crowds looked similar in scale in television images supplied by the campaigns.
The police made it clear they would be giving no estimates. In any case, nothing in the race has yet shifted the underlying polling data: Sarkozy appears to be on course for a clear defeat after one term.
Sarkozy was banking on large numbers to support his theory that the polls are failing to take into account a "silent majority" on the right.
"Tomorrow, I'm going to bring together many, many, many of the French. I can feel mobilisation. I can feel the popular will," he said Saturday.
"I want tomorrow to address the silent France: Those who don't smash up bus shelters; those who just want to be allowed to work. To those who love their families, the land. Those who love their country," he said.
But in his speech on Sunday Hollande denounced any attempt to set one half of France against the other. "There is not a noisy minority on the one side, and on the other a silent majority," he said.
The final week of campaigning will also be the last chance for the trailing candidates to make their mark before they are eliminated.
Communist-backed left-winger Jean-Luc Melenchon has made the surprise breakthrough of the campaign, and his Left Front party is battling Marine Le Pen's anti-immigrant, anti-EU, far-right National Front for third place.
Recent polls have both at between 13% and 17% – some giving Melenchon a slight advantage, some Le Pen – despite the latter's bold claim that she will win double the hard left's score.