World No.1 Barty suffers shock defeat in first round of Olympics
Barty in action.
"It's an amazing feeling, I still can't believe it," said Sorribes Tormo, who will go on to face France's Fiona Ferro in the second round.
"It's something incredible for me. It's something that I've been dreaming of all my life, being here and even more so beating the world number one. I'm super, super happy."
Barty could potentially come up against Sorribes Tormo again in the quarter-finals of that competition. Sorribes Tormo and Paula Badosa are in first-round action later on Sunday.