The Frenchwoman showed great composure, thrashing the Pole in the unforced errors stats (Cornet's 7 to Świątek's 33) and securing a 6-4, 6-2 win against the reigning WTA ranking leader.
The defeat has put a stop to Świątek's victory streak at 37 matches. It was the longest winning run in women's tennis since 1997 when Martina Hingis also won 37 matches on the bounce.
The match against Cornet is Świątek's first loss in four months. On Thursday, she beat Dutch Pattinama Kerkhove 6-4, 4-6, 6-3 in the Grand Slam's second round.
Ealier today, another Polish tennis player, Magdalena Fręch, crashed out of the tournament after losing to Romania's Simona Halep in a women's singles match in the Wimbledon third round.
(pjm)