Rio de Janeiro, State of Rio de Janeiro, Brazil, 5 August 2016 | tennis.com.au

Daria Gavrilova will open her Olympic campaign against world No.1 and top seed Serena Williams.

It is the toughest of draws for the young Aussie, who lines up against the reigning Wimbledon champion and the winner of the last singles gold medal in London 2012.

Williams and Gavrilova have met just once, a match played more than three years ago in the first round of the 2013 Qatar Open in Doha.

Williams won that encounter 6-2 6-1.

Gavrilova’s fellow Aussie Sam Stosur, the 13th seed, begins against Latvia’s Jelena Ostapenko.

Should the seedings hold, Stosur would go on to face No.2 seed Angelique Kerber in the last 16.

In the men’s draw, Sam Groth was handed the toughest opponent in the form of No.8 seed David Goffin.

Jordan Thompson faces Britain’s Kyle Edmund, Thanasi Kokknakis will tackle Gastao Elias of Portugal and John Millman lines up against Lithuanian Ricardas Berankis.

Should he win, Millman faces a likely battle with No.4 seed Kei Nishikori of Japan.

> view the complete Olympic singles draws

In doubles, Australia’s women have been dealt difficult draws.

Stosur and Gavrilova will face Swiss No.5 seeds Martina Hingis and Timea Bacsinszky, while Anastasia and Arina Rodionova – a late call-up into the draw – will battle No.7 seeds Ekaterina Makarova and Elena Vesnina of Russia.

In the men’s draw, Australia’s pairing of John Peers and Chris Guccione face Argentinean team Juan Martin del Potro and Maximo Gonzalez.