A ruthless Petra Kvitova trampled on the hopes of the host nation with an emphatic 6-1 6-4 defeat of Ashleigh Barty to reach her second Australian Open semi-final on Tuesday.

The double Wimbledon champion silenced home fans at a packed Rod Laver Arena, who had barely settled in their seats before the first set was over in a dizzying 27 minutes.

The eighth-seeded Czech faced stiffer resistance from Barty in the second but broke the former cricketer in the ninth game before sealing victory when Barty, seeded 15th, netted a return.

The Czech, who reached the 2012 semi-finals at Melbourne Park, returned to the last four of a Grand Slam for the first time since claiming her second Wimbledon title in 2014.

She will play unseeded American Danielle Collins for a place in Saturday's final.