Upon the outbreak of the coup Justino remained neutral, but at night on the 31st he already had forces moving through the hinterland as part of his battle plan. At 23:00 the 15th Infantry Regiment was already in Goiana, entering Pernambuco. Both the battle plan and a hit list of arrests were ready days earlier. The IVth Army's silence and its prohibition of demonstrations were signs of which side it favored.
At dawn on the 1st of April Goulart phoned Justino, said he had the other three armies under his control (a lie) and asked of his. Justino replied it was "well, in rigorous readiness, President". His officers, overhearing the conversation, almost laughed.
At 09:00 the IVth Army made its stance public, backed by the 3rd Naval District and 2nd Air Zone. The Naval District's position was a surprise to Arraes, who expected it to be legalist. In the ranks there was no legalist reaction of note. It was a one-sided military sweep against civilian resistance.

The IVth Army's interventions in the hinterland seem like a random list of cities, but as explained in the Oral History, they were chiefly an invasion of Pernambuco from north and south, where the situation was under control; the governor of Alagoas was part of the coup and that of Paraíba folded under pressure and his police was employed. It was expected thar Arraes would try to move forces through the state and thus the roads were taken over. Meanwhile the capital's garrison moved against Arraes himself.

Peasant Leagues and others made a handful of insurrections, one weaker than the other. The greatest was in Vitória, where they occupied the town hall, media and rail station. The other locations were Caruru and Rio Tinto, the latter quelled by the police. On the 2nd the leftist mayor of Propiá was seen with an armed crowd but arrested by the 28th Caçadores.
And in southern Pernambuco there wasn't even an attempt: armed peasants could be seen in the roads but Gregório Bezerra, leading communist peasant leader, told them not to try. They wouldn't receive weapons from the state government, as expected. The 20th Caçadores left troops in the latifundia on their side of the border and then took part on the manhunt against Bezerra.

The 15th Infantry headed to Recife, where the IVth Army controlled all access and had an overwhelming presence. The 2nd Police Battalion defected. In the morning the 14th Infantry, 1st/7th Howitzer, 7th Army Police Company and a mech recon squadron besieged Arraes in his palace. The infantry was the left flank and the howitzers (who'd been rigorously trained for internal conflict months in advance) the middle. The 3rd Naval District was to be the right flank but didn't show up. The palace had a company or battalion of guards with MG nests. Justino didn't want bloodshed and first attempted diplomacy. Arraes stalled.
At 13:30 a platoon of the 1st/7th Howitzer rushed to the palace. The policemen were ordered to give their guard posts to the Army and obeyed. By at most 16:00 Arraes had been removed.
His police commander, Colonel Trench, entrenched himself in the HQ, but four light tanks made the defenders immediately rout and at 14:30 the HQ was captured.

Seixas Dória, governor of Sergipe, met the same fate. Rio Grande do Norte's governor sided with Justino while the mayor of Natal had to be overthrown. Other governors, by their poverty and dependence on the federal government, made declarations favorable to it but changed their stance under military pressure: those of Bahia and Piauí. The latter, before the declaration, had to concede to his police being spread through the capital as part of the security plan; little did he know the 25th Caçadores thus had a company ready to take the police HQ and another his palace, which wasn't necessary. Bahia's later thrived under the new regime.

General Justino thus became the most powerful man in the Northeast.