Sorribes Tormo, who only has one career title and has never gotten further than the second round in any major singles tournament, beat the world No. 1 Barty, 6-4, 6-3.
Barty had 55 unforced errors in 19 Giochi. She explained the heat was getting to her during the match.
“It’s brutal, like an Australian summer,” lei disse Australia’s Channel 7. “I enjoy the heat and love playing out here in these conditions but wasn’t meant to be.
“It was a tough day. A disappointing day. I can’t lie about that. I can’t hide behind that fact that I wanted to do really well here. Today wasn’t my day.
“Just loose. I knew I wanted to try to take the match on (e) it would be a fine line of not pushing too hard and not getting in the patterns I didn’t want to get stuck in. (ero) too erratic.”
The 25-year-old was making her first Olympics appearance and was the top seed coming into the Games after having already won Wimbledon and made it to the quarterfinals of the Australian Open in 2021.
Sorribes Tormo defeated France’s Fiona Ferro in straight sets, 6-1, 6-4. She will play the Russian Olympic Committee’s Anastasia Pavlyuchenkova in the third round.