Google Argentina's domain name was bought by a web designer while the site was out of action for two hours in the country last Wednesday, APA reports citing BBC.
Nicolas Kurona, aged 30, said he managed to buy Google.com.ar through a normal, legal process.
"I never imagined that it was going to allow me to buy it," he told the BBC.
Google Argentina told the BBC: "For a short term, the domain was acquired by someone else." It added it had regained control of the domain very quickly.
The story started when Nicolas was at his desk on the outskirts of Buenos Aires on Wednesday night, designing a website for a client.
He started getting messages on WhatsApp that Google was down.
"I entered www.google.com.ar into my browser and it didn't work," he said. "I thought something strange was happening."
He decided to go on to the Network Information Center Argentina (NIC) - the organisation responsible for operating the .ar country code domains. He searched for Google - and up popped Argentina's Google domain available for purchase.
Despite thinking it would not work, he "followed the steps and then I received an email with the purchase invoice", he said.
Nicolas shared the NIC invoice with the BBC. Google Argentina's domain name was acquired for 270 pesos (£2.08/$2.90).