MOSCOW — The European Court of Human Rights ruled in favor of a Russian man on Tuesday who was detained during a political rally in Moscow in 2012 and who was later sentenced to two weeks in jail for jaywalking.

The ruling was a rebuff to the Russian practice of cracking down on political rallies with harsh fines and jail time. It undermined a central element of Moscow’s narrative of the clashes — that unruly protesters had set off the violence, thus justifying new laws cracking down on public assembly.

The police arrested about 400 people, including the plaintiff in the case, Yevgeniy Frumkin, after scuffles broke out at the rally, on May 6, 2012, on Bolotnaya Square in Moscow.

The demonstration followed a series of large, peaceful protests by people who opposed the election in March 2012 of Vladimir Putin to a third term as president, and who suspected fraud during voting.

The rally was permitted to take place. But police officers herded tens of thousands of people from a large avenue into a tightly confined zone in a park, creating a bottleneck, and scuffles with the police ensued.

The violence, political analysts say, became politically advantageous for Putin, who defended the subsequent arrests and prosecutions of protesters on various charges. It also precipitated a series of laws that constricted the right to assemble, part of a general tightening of political screws in Russia since Putin’s return to power.

Rights groups have called the measures a throwback to Soviet-era authoritarianism, and they say the police intentionally created the bottleneck in the parade route to cause a dangerous and unruly scene.

The European Court of Human Rights ordered the Russian government to pay Frumkin $27,000 in damages and $7,500 in expenses.

Russia is a party to the treaty that established the court in the 1950s, and it has usually paid fines the court imposes, even in cases where officials said the decisions were biased.