Qiang Wang claimed the first big scalp on day one of the French Open with a straight-sets defeat of Venus Williams.
Wang pulled off a first-round shock on Suzanne-Lenglen Court, beating the ninth seed 6-4 7-5 on a warm Sunday in Paris.
Williams bowed out in the first round of the Australian Open and experienced the same fate in the second grand slam of the year.
The seven-time major singles champion, a runner-up at Roland Garros 16 years ago, was broken twice in each set and paid the price for making 35 unforced errors.
Wang, 85th in the rankings, lost to Williams in the opening round on the clay in the French capital 12 months ago and in the second round at Wimbledon, but gained sweet revenge.
The unseeded Chinese outsider, who fought back from 3-0 down in the second set, will come up against Petra Martic in round two following a composed performance against the American veteran.
Konta also out on opening day
British number one and 2017 Wimbledon semi-finalist Johanna Konta was also knocked out in the first round at Roland Garros by Yulia Putintseva in straight sets.
Konta, seeded 22, was beaten 6-4, 6-3 by the world number 93 after hitting 32 unforced errors.