Reade, a three-time senior world BMX champion, headed to South America having won the opening round in Manchester but was not about to leave it there.
The 24-year-old once again topped the podium, finishing ahead of London 2012 gold medallist Mariana Pajon and Dutch rider Laura Smulders in Saturday's elite women's final.
Reade, who finished sixth at the London 2012 Olympics, also triumphed in the time trial Superfinal 24 hours earlier, as she did in Manchester, and sits top of the overall standings with a perfect record.
And Reade insists she has no intention to relinquish top spot any time soon, while also keeping an eye on New Zealand and July's BMX World Championships.
"I'm so, so tired but at the same time so happy," Reade said.
"Obviously when someone's Olympic champion they have got a target on their back you want to beat them, it makes it all the more special.
"I want to become overall Supercross champion and world champion as well."
Fellow London Olympian Liam Phillips endured a tougher time of things in Argentina however as he suffered a crash with American Donny Robinson in the elite men's quarter-final.
The 24-year-old, who had finished fifth in Friday's time trial, was stretchered away and taken to hospital for precautionary scans which showed that no serious injuries were suffered.
© Sportsbeat 2013