Defending champion Keys beats Pliskova to reach fourth round

Australian Open defending champion Madison Keys has raised her game in the Melbourne Park heat to beat Karolina Pliskova 6-3 6-3 and reach the fourth round of the Grand Slam on Saturday.

On a day forecast to hit 40 degrees Celsius (104F), American Keys avoided the worst of the conditions as she dismantled the Czech in 75 minutes in the early match at Rod Laver Arena.

The ninth seed will meet fellow Florida-based American Jessica Pegula, who similarly coasted into the last 16 with a 6-3 6-2 win over Russian Oksana Selekhmeteva at Margaret Court Arena.

Keys and sixth seed Pegula are good friends away from the tour and produce a tennis podcast together with American players Jennifer Brady and Desirae Krawczyk.

Both Keys and Pegula said they had no problems with the conditions, despite temperatures hovering above 31C well before midday.

"I was excited about the heat, being Floridian," Keys said on court.

Keys also revealed she and Pegula were due to a produce a podcast before their match. The friendship will be put aside when they meet in a couple of days.