Serena Williams continues her long quest for a record-equalling 24th Grand Slam when the COVID-19-delayed 2021 Australian Open begins on Monday, four years since her last major triumph in Melbourne.

It may be this season or never for Williams, who turns 40 in September and will have to conquer a field bursting with young talent headed by US Open champion Naomi Osaka, home favourite and World No. 1 Ashleigh Barty and defending champion Sofia Kenin.