Iga Swiatek admitted the pressure of the world number one tag got to her after crashing out of the Australian Open in the fourth round to Wimbledon champion Elena Rybakina.
The Russian-turned-Kazakh has spoken of her frustration at not being scheduled on the main courts since her success at the All England Club and, on Rod Laver Arena, she produced a big-stage performance to win 6-4 6-4.
Rybakina, who would be in the top 10 had Wimbledon offered ranking points, dropped only six points on her first serve during the match and recovered from 3-0 down against a frustrated Swiatek.
The result, coupled with defeats for Ons Jabeur, Rafael Nadal and Casper Ruud, means for the first time in the open era, the top two seeds in both the men's and women's draws have lost before the quarter-finals.