Edwards is looking to bounce back and win the tournament having twice come up short in title fights against Johnny Eblen in 2023 and 2024.
He returned to form, knocking out Impa Kasanganay in the second round in April, and brought that confidence into the contest with Silveira.
The pair traded leg kicks in the early stages, with Silveira sweeping Edwards off his feet.
Edwards responded, taking control of the stand-up, defending takedown attempts and hurting Silveira with a knee to the body.
Roared on by his brother and former UFC welterweight champion Leon at cage-side, Edwards hurt Silveira with a straight left and secured two takedowns of his own.
As the fight entered the closing stages with Edwards controlling Silveira on the ground, he gave a thumbs-up to the television cameras, signalling his confidence in victory.