Rebecca Peterson began the Olympics by defeating her regular doubles partner Maiar Sherif the day before yesterday.
But today, when she faced 15-seeded Kazakh Jelena Rybakina, it became too tough for Peterson.
The 25-year-old broke Rybakina's serve early in the first set and went up to 2-1, but then the fun was over.
Better second set by Peterson
Rybakina broke right back and then took four more straight games and won the first set 6-2.
In the second set, Peterson played and hung on for a long time.
But Rybakina, who reached the quarterfinals of the French Open earlier this year, broke Peterson's serve and went up to 5-3, and then served home the match.
With that, Peterson's Olympics are over.