Josef Martinez’s goal was assisted by Julian Gressel in the 13th minute. Gressel was played in by Ezequiel Barco.
Pity Martinez increased the lead to 2-0 with a penalty kick in the 31st minute when he was taken down in the box after being sent through by George Bello.
Josef Martinez added another on an assist from Hector Villalba in the 46th minute.
Pereira’s first was from short range in the 72nd minute.
Williams scored with a header on an assist by Amir Bashti in the 95th minute before scoring again in the 101st minute. Bashti ran onto a cross from Brek Shea before putting the ball back into the penalty box to Williams on his first goal. The second came from a cross by Brandon Vazquez.
Pereira finished with his second goal in the 109th minute. It also was from close range after he tapped in a shot by Williams that hit the post.
In addition to Pity Martinez, Pereira and Bashti, other debuts were made by Anderson Asiedu, the team’s first pick in this year’s draft, Shea and Brendan Moore.
Atlanta United’s starting 11 was goalkeeper Brad Guzan, centerbacks Michael Parkhurst, Leandro Gonzalez Pirez and Miles Robinson, wingbacks Gressel and Bello, midfielders Gonzalo Martinez, Eric Remedi, Asiedu and Barco and Josef Martinez as the striker.