Sofia Kenin launched her Australian Open defence with a 7-5 6-4 win over Maddison Inglis on Tuesday, while Paula Badosa bowed out with a 6-7(4) 7-6(4) 7-5 loss to Russian qualifier Liudmila Samsonova.

Kenin found the going tough against the plucky Australian wildcard as she was broken twice and slumped to a 3-1 deficit early before steadying in the sunshine at Rod Laver Arena.

The American fourth seed double-faulted on the first of three match points but finally sealed the contest as she marched forward to thump a backhand drive volley.

Kenin will meet either Kaia Kanepi or Anastasija Sevastova for a place in the third round.

-Badosa sent packing after COVID-19 ordeal-

Badosa, the only Australian Open player to contract COVID-19 in the leadup to the Grand Slam, had a fraught buildup to the tournament, testing positive to the novel coronavirus while in quarantine last month.

The Spanish world number 70's infection saw her transferred to a separate "health hotel" where COVID-19 cases are isolated, and the clock on her mandatory period of isolation was restarted.

Badosa complained bitterly about the experience, saying it was "far and away the worst" of her career.

Paula Badosa only Australian Open player to contract COVID-19 in the leadup to the Grand Slam.   -  GETTY IMAGES

Unable to compete in any of the leadup events, Badosa was short of match fitness when confronting Samsonova on a warm afternoon and was dragged into a dogfight by the world number 130.

She battled into a position to serve for the match at 5-4 in the deciding set but ended up double-faulting on break point.

Fatigue appeared to take it toll as she served to stay in the match, and Samsonova took full advantage, running Badosa ragged until the Spaniard sprayed a shot wide on match point.

Samsonova advances to a second round match against last year's finalist Garbine Muguruza.