Pakistan, Jan. 27 -- Jessica Pegula sent reigning champion and podcast co-host Madison Keys spinning out of the Australian Open on Monday while Jannik Sinner aims to avoid the same fate and reach the quarter-finals in stifling heat.

In temperatures approaching 30C in Melbourne, fifth seed Lorenzo Musetti set up a last-eight showdown with Novak Djokovic.

Keys and Pegula launched day nine in a clash at Rod Laver Arena between two Americans who know each other well.

They are good friends and also host a tennis podcast together, "The Player's Box", and had even been planning to record an episode on the eve of their match.

All that was put aside as a clinical Pegula dominated 6-3, 6-4 to set up a last-eight encounter with another American ...