Elena Milashina, a daring Russian reporter beaten unconscious and doused in liquid iodine last year, said she has bid farewell to far too many journalists, activists and opposition figures who died an untimely death.

But never, she said in a phone interview from Moscow, had she seen anything like the scene on Friday on the streets of the sleepy Maryino neighborhood on the outskirts of the Russian capital.

“This was the most optimistic funeral I can remember,” said Ms. Milashina, 47, citing the large crowds and a palpable sense of unity. “There was no grief. There was this surge of inspiration that we are all together, and that there are many of us.”

The funeral of the opposition leader Aleksei A. Navalny on Friday may come to be remembered as a seminal moment in Vladimir V. Putin’s Russia. It was a day when the president’s decades-long nemesis was laid to rest, underlining Mr. Putin’s dominance; but it was also a day when an ocean of pent-up dissent re-emerged, if only for a few hours, on Moscow’s streets.

The hope for a better Russia “died the day that we all learned that they killed Navalny,” Ms. Milashina said. “But today, I felt — you could really see it — that it was resurrected.”

Mr. Navalny spent his last three years in prison, under increasingly inhumane conditions. But many opposition-minded Russians still saw him as their Nelson Mandela, poised to someday ascend as the leader of a democratic Russia.