Footage showed Mr Navalny, 44, being met by police officers at passport control minutes after landing in the Russian capital. A statement from the state penitentiary service later confirmed Mr Navalny had been detained "pending a court hearing on January 29”.
A few moments before his arrest, Mr Navalny answered questions in front of a backdrop showing the red towers of the Kremlin. “This is the best day of the last five months,” he said. “I’m not afraid, because I know I’m right. I’m not afraid of anything.”
Sunday was the first time the Putin critic had set foot on Russian soil since being flown to Germany for emergency medical treatment in August after collapsing on an internal flight in Siberia. Several European laboratories later determined he had been poisoned by a nerve agent of the Novichok class, used in previous attacks linked with the Russian state.
The opposition politician had vowed to return despite the likelihood he would be arrested.
It had promised to be a day of drama. In the event, the Kremlin decided it would do theatre.
Officials employed an elaborate ruse, redirecting his plane at the last minute and flatfooting journalists and a few thousand supporters waiting in a different airport.
Earlier in the day, Moscow Vnukovo, the original destination airport, had been ostentatiously prepared for battle — complete with riot police, dozens of police vans, guard dogs, and concentric rings of metal shields. Only with the plane already descending did it become clear that something was not right.
First, the plane veered off course. Then social media connected with law enforcement said it was being diverted. Later, the airline and airport representatives confirmed the plane was heading north to the main city airport, Sheremetyevo.
Mr Navalny’s risky move to fly following his near-death experience had been variously likened to the arrival of Vladimir Lenin at Petrograd station before the October revolution in 1917 or to the struggle of Nelson Mandela in apartheid era South Africa.
Even more excitable opinions talked of the second coming of Jesus Christ — an interpretation not wholly inconsistent with the politician’s calls to devoted supporters to greet him at the airport.
Instead, the opposition leader was welcomed into Russia by another old friend: law enforcement.
That outcome was always the most likely, and had been heavily trailed by authorities. On 12 January, the state penitentiary service announced it had placed the Kremlin foe on a wanted list after supposedly breaking parole, and would look to arrest him on arrival. Another state agency, the investigative committee, made a parallel claim to Mr Navalny’s freedom, alleging he was guilty of embezzlement from funds donated to his anti-corruption foundation.
The legal justifications push the bounds of credibility. But Mr Navalny’s own lawyers concede either one of the claims could result in a lengthy prison sentence from Russia’s infamous court system.
As such, the immediate future for the opposition politician looks reasonably bleak. Supporters insist that even in the now likely event that he is imprisoned, he will be able to plot a new future from his cell in the same way as Nelson Mandela. Mr Navalny will hope his walk to freedom will be shorter than the 27 years the anti-apartheid campaigner took.
What is certain is that the Putin critic’s return and arrest reignites political life in Russia — just as the Kremlin approaches potentially tricky parliamentary elections this year. Mr Navalny’s organisation is expected to be active in trying to defeat pro-Kremlin candidates.
Amnesty International have already responded to the fact of the opposition leader’s arrest by declaring him a prisoner of conscience. Jake Sullivan, US president-elect Joe Biden's pick for national security adviser meanwhile called for his release. "The perpetrators of the outrageous attack on his life must be held accountable," he wrote in a tweet.
The Kremlin has given little sign that it intends to take such advice on board. On Sunday evening spokesman Dmitry Peskov feigned ignorance as he answered reporters’ questions.
“He was arrested? In Germany? I wasn’t aware," he said.