The choice given to the Philippine marines manning two tanks stopped on Ortigas Avenue Sunday afternoon, as tensions first began to build, was simple. If they wanted to reach their objective, they would have to roll over the crowd that was enveloping them.

In its ranks were Catholic nuns reciting the words, "Hail Mary, full of grace. . . . " There were priests with heads bowed in prayer and young women offering orchids to any soldier who would take them.

So the marines bluffed. Over and over, they fired up their tanks' mammoth diesel engines and edged forward. Shouts of "Sit down! Sit down!" would ring out. People would drop to the pavement and the tanks would stop. Applause and cries of rapture would go up at this new victory.

In the end, after four hours, the tanks and the armored column of about 1,000 marines they were leading went back to their barracks, having unexpectedly met with a remarkable display of citizen activism by supporters of opposition leader Corazon Aquino.

In the early hours of Monday morning, troops came back elsewhere, according to widespread reports, using tear gas and truncheons against crowds. But those troops also failed in their mission.

The withdrawal of the military in the confrontation on Sunday brought jubilation.

"Liberation day!" declared a young man surveying the scene with others from atop a bus.

The danger to the crowd was probably not as high as it might have seemed. From the start it was clear that the marines, many of whom had been flown to Manila only days ago from duty fighting Communist insurgents on Mindanao Island, did not have their hearts in the task. Many flashed the laban ("fight!") hand signal of the opposition.

The crowd treated them not with contempt but as errant brothers they hoped would return to the fold.

"We are all Filipinos -- there is no fight here," shouted one man as a column of marines weighted down with M60 machine guns and a bazooka passed by.

The marines left Ft. Bonifacio, a major military base in Manila, in early afternoon. Their mission, officers said, was to proceed to Camp Aguinaldo, the Defense Ministry headquarters where military rebels who support Aquino's claim to the presidency were in control.

Their tracked vehicles chewed up soft pavement as they rumbled across the city through light Sunday traffic on Epifanio de los Santos Avenue. Crowds of peopled watched from overpasses and sidewalks.

At the intersection with Ortigas Avenue, about one mile from the camp, Aquino supporters had blocked passage with about two dozen commandeered buses. As the crowd of about 20,000 looked on, the marines turned off the avenue and crashed through a wooden fence, entering a vacant lot of about 10 acres in an apparent effort to skirt the barrier. Two tanks broke through a wall at the field's far side and entered Ortigas Avenue. The crowd closed in and that was as far as the soldiers got.

The marine commandant, Brig. Gen. Artemio Tadiar, dressed in a camouflage jump suit, waded into the crowd around the tanks and tried to work out passage with a businessman who had emerged as a spokesman. "If we can't clear this and it gets dark, there will be trouble," he told reporters later.

The crowd's spirits were high and the general drew applause when he climbed atop a tank to address them with a loudspeaker.

"Let us just move," he pleaded.

"No! No!" the crowd responded.

He tried again: "We want to go on quietly and I want to assure you there'll be no trouble." That appeal also was rejected.

Women moved among the soldiers, giving out purple orchids. A marine packing an M16 rifle stuck one in his shoulder harness. Sandwiches were passed forward by the crowd and given to the marines.

"Look at the faces of the soldiers. They are not the faces of people who want to fight," said Freddie Aldeguer, a salesman for a pharmaceutical company.

The first sign of victory for the crowd came when the tanks lurched back through the hole in the wall about 4:45 p.m. and rejoined the rest of the force in the field. "It seems we cannot go forward without hurting someone," a colonel said.

People began feeling bolder. Ignoring gestures of admonition, women strode into the field to deliver marigolds to sheepish soldiers.

When a helicopter set down in the center, they rushed toward it and chanted, "Cory! Cory!" at the men who got out.

A colonel said there would be no violence from the soldiers. "We told them not to follow unlawful orders," he said. "Killing people is unauthorized. That's why we didn't push through. Some of us have relatives in the opposition. Some of us have relatives in the mountains," a reference to the Communist insurgency.

The gathering acquired even more of a fiesta atmosphere as dusk approached. A family posed for a photo against an armored car. Two men volunteered to a reporter that the Filipino people would welcome U.S. intervention.

The marines began leaving as darkness fell. The buses were removed and the crowd parted. The tanks, armored cars, personnel carriers, jeeps and trucks picked their way through amid applause.

People grabbed the hands of soldiers walking out, often drawing warm smiles in return, and joined the convoy in a victory march as it rolled back toward Ft. Bonifacio.

It is unclear why the order to withdraw was given. President Ferdinand Marcos said tonight he gave it after the rebels pleaded with him not to use force. But to the crowd, the victory was all theirs.