The Brazilian was close to perfection in his heat, scoring 19.43 out of a possible 20 in shifting waves of just over a metre in length.
"I’m so happy right now," De Souza, known as 'Mineirinho', said afterward.
"Last year was really big and today is only four feet, but still very fun. I just had fun and caught the good barrels and the judges liked it.
"I’m having a good year. Every year, I focus on what I need to improve on and go out and work on it. I feel more confident at every spot, I feel strong and have good boards."
Legendary 40-year-old surfer Kelly Slater was also among those to perform well in their heat and advance directly to the third round as a result.
"I actually caught the last plane I could have caught to make my heat and I barely made it this morning," Slater said, after a tight schedule almost led to the American missing day one.
"It’s not often that the waves in California are better than Tahiti, but there hasn’t been a whole lot of surf here and we’ve had pretty good waves at home.
"It doesn’t look like there’s a hot forecast for this year which is a shame, but there’s still fun surf to be had. It’s Teahupo’o and you can sometimes take for granted how beautiful the waves are here.
"I’ve been coming here since ’93 so it’s about 20 years and I still love it, it’s still so raw. There’s no real big business here. It’s all families and we stay with them and it’s still a very special place."