Australia's Paige Greco and Emily Petricola win Tokyo Paralympics cycling gold

Australia has made the perfect start to the Tokyo Paralympics, winning the first two gold medals of the Games.

Key points:

• Paige Greco broke her world record in the C3 3,000 metres individual pursuit final
• Emily Petricola beat Shawn Morelli of the US to win the C4 3,000m pursuit gold-medal race
• Greco and Petricola entered the Games as defending world champions in their events

Track cyclist Paige Greco broke her world record in the C3 3,000 metres individual pursuit at the Izu Velodrome.

A few minutes later, Greco's teammate Emily Petricola lapped American rival Shawn Morelli to take out the C4 3,000m pursuit.

Compatriot Meg Lemon lost her C4 pursuit bronze medal ride-off to Canadian Shawn Keely.

Greco, 24, easily beat China's Wang Xiaomei in their gold medal ride-off on Wednesday.

LIVE UPDATES: Keep up with all the action in the pool on Day 1 of the Paralympics

The Adelaide cyclist, who has cerebral palsy, clocked three minutes and 50.815 seconds and Wang rode 3:54.975.

Greco also broke her world record earlier on Wednesday when she qualified fastest in 3:52.283.

Petricola made a shaky start against Morelli and looked in trouble when she was 0.951 of a second down after the first lap.

But the 41-year-old from Queensland, who was diagnosed with multiple sclerosis 14 years ago, then dominated their ride-off and caught Morelli well inside the last kilometre.

Petricola also broke her world record when she qualified fastest in 3:38.061.

Lemon trailed early against Keely and could not pull back the deficit, losing by more than a second.

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All three Australians are making their Paralympic debuts, while Greco and Petricola came into the Games as defending world champions in their individual pursuit categories.

AAP