American teen Ariel Hsing upset 1983 world champion Ni Xia Lian of Luxembourg on Sunday to reach the third round in Olympic table tennis.
The 16-year-old Hsing, who has gained attention because of her friendship with billionaires Bill Gates and Warren Buffett, defeated Ni 4-2 and will now face second-seeded Li Xiaoxia in the third round.
Li is among the gold medal favorites along with Chinese teammate Ding Ning.
Hsing has talked about using the London Olympics - her first - as preparation for the Rio de Janeiro Games in four years. But her time has come sooner than she expected.
The 49-year-old Ni is a two-time European champion and was a world champion playing for her native China 30 years ago.