So Venus Williams, who mixes tennis with interior design, gets beaten by a 21-year-old Serbian, Jelena Jankovic, ranked 29 in the world, who mixes tennis with university in Belgrade. No shock there really, as Williams has long demonstrated an uncanny ability to lose matches she should win.
Her 10 previous appearances here counted for little as the hard-hitting Jankovic claimed the match 7-6, 4-6, 6-4 to send the defending champion back to America (after her doubles) to join her injured sister Serena.
While Williams lost the first set and won the second before taking a 2-0 lead in the third, American hopes were briefly rekindled. But a litany of unforced errors gave Jankovic a lifeline. She not only levelled but took a 5-3 lead in the third set before closing out the match.
The Williams sisters may, before the US Open in a couple of months' time, just try to work out how their world domination of a few years ago has been so undermined in such a short time.
Jankovic, for her tenacity, is rewarded with a meeting with Russia's Anastasia Myskina, the winner of that match going into a quarter-final with possibly the top seed and world number one, Amelie Mauresmo.
Although Williams is out, the other protagonists remain steadfastly in contention, and today several wannabes get to tilt at the bigger names.
Kim Clijsters meets the 17-year-old Pole Agnieszka Radwanska, who arrived here as a 217-ranked wild card. Her age, rank and size have not prevented the newcomer cutting a swathe and getting this far without dropping a set.
That's a long run for a debutante and given Radwanska has spent most of her career at a professional tier below the top level, the Belgian second seed is unlikely to be much troubled.
While Justine Henin-Hardenne meets Daniela Hantuchova, Mauresmo takes on Ana Ivanovic, and Maria Sharapova faces Italy's Flavia Pennetta, another less-vaunted player who has caused ripples in both Roland Garros and the first week at Wimbledon is 17-year-old Nicole Vaidisova.
The 10th seed meets the 27th seed, Ni Li, the first Chinese player to be seeded at Wimbledon.
One of an assembly line of Eastern European baseline hitters trained in Nick Bollettieri's Floridian boot camp, Vaidisova enhanced her reputation last month in Paris by removing both Williams and the French darling, Mauresmo, from the tournament.
Invariably compared to Sharapova because of her blonde hair and statuesque physique, Vaidisova is now in line to earn herself a potential quarter-final meeting with Clijsters.
"I came very close in the French Open," she said. "That is a good sign, a good experience against the top players. It's one thing to play against the top players and another thing to beat them."
She has already gone one round further than her debut last year, when she was beaten by the now-departed Svetlana Kuznetsova in three sets, but with her grounded mentality and the physical ability to hurt any player in the draw, the quietly advancing Prague resident has not only the ammunition to take out Li but also enough self-belief to ensure a crack at Clijsters would be far from one-sided.