“I told the government that the probability of this is as high as the birth of a dog with five legs,” said Geert Ahrens, head of the organization’s Election Observation Mission here.

There were moments of drama straight out of Gogol. In one recount witnessed by a Western observer, some members of a counting committee, apparently in an attempt at filibustering, wandered off and were missing for hours. The committee chairman was declared sick. Then came a rumor he had had a heart attack.

Finally, in sheer frustration after hours of waiting, an official ripped open an envelope marked as containing ballots for Mr. Sargsyan. The ballot on top of the pile was for his opponent, Mr. Ter-Petrossian, and other officials immediately rushed to close the envelope. “I can only assume it was a bad count that someone did not want reopened,” the observer said.

Even so, when seen in the context of the broader region, Mr. Ahrens said, “I’ve seen worse.”

“We won the election,” Mr. Ter-Petrossian said Thursday, sitting in a cafe, the Swan Lake. He added that he had received 65 percent of the vote, a figure that Mr. Ahrens said was “not grounded in any factual evidence.” Mr. Ter-Petrossian’s aides, who refer to him as “the president,” seemed to have fully internalized the figure nonetheless.

The crowds have only seemed to grow since the first post-election rallies, particularly since the day last week when a government-organized rally broke ranks to join them.

Mr. Ter-Petrossian, who is fond of dramatic entrances, rushed onto the stage, as Beethoven’s “Ode to Joy” blared from loudspeakers. He spoke for hours, revving up the crowd of angry grandmothers, bored young men eating sunflower seeds and a variety of Armenian professionals.

Mr. Ter-Petrossian, who was president from 1991 to 1998, presents himself as the one to rescue the country. For nine days he has slept in his Lincoln Town Car, parked near the protesters’ camp, and he calls the protests “a clear, classic bourgeois, democratic revolution.”