Two-time Australian Open champion Victoria Azarenka's long-awaited return to Melbourne did not go according to plan after she was bundled out by Laura Siegemund.

Melbourne Park has been a happy hunting ground for former world number one Azarenka, who won back-to-back Australian Opens in 2012 and 2013.

The Belarusian star, however, missed the 2017 and 2018 tournaments amid a custody battle over her son.

But Azarenka made her first Australian Open appearance since 2016 on Tuesday, though it ended in a 6-7 (5-7) 6-4 6-2 opening-round defeat on Melbourne Arena.

Azarenka, who was broken in a decisive sixth game of the final set, hit 29 winners but 40 unforced errors as she exited the year's first grand slam after two hours, 42 minutes.