Australian Anna Meares has again proved she is the queen of track cycling, breaking her own 500m time trial world record.

Meares became the first woman to go under 33 seconds for the event on Saturday when she made the most of the high altitude at the Mexico World Cup round.

The 30-year-old clocked 32.836 seconds to break her own mark of 33.010, set at last year's world titles in Melbourne.

She led an outstanding Australian performance on day two of the World Cup round, with Matthew Glaetzer scoring a breakthrough gold medal in the men's sprint.

Luke Davison also won the men's omnium and Rebecca Wiasak took out the women's 3000m individual pursuit.

"I just wanted it. I wanted it really badly," Meares said of her latest world record.

"It's really weird. It's taken me nearly 10 years to improve just over a second in the discipline.

"In Athens in 2004, I was 20 years old and became the first women to ride a sub-34 (33.952) and now, 10 years later at 30 years of age, I'm the first to ride a sub-33.

"I am just so proud."

Meares' gold medal and world record in the 500 at the Athens Olympics confirmed her star status in track cycling.

She was also the last Olympic champion in the event before it was controversially taken off the Games program.

This latest world record emphasises that Meares is on target for next year's world titles.

She had a 16-month sabbatical from international competition after her historic sprint win over fierce British rival Victoria Pendleton for the gold medal at the London Olympics.

Glaetzer also starred on day two and was among four men who went under the flying 200m world record in sprint qualifying.

Francois Pervis of France qualified fastest in 9.347 and Glaetzer was second in 9.459, beating the old world record of 9.572.

Frenchman Kevin Sireau had set that mark four years ago.

Glaetzer then progressed through the match sprint rounds and scored a massive scalp in the ride-off for the gold medal.

He beat British star Jason Kenny, the reigning Olympic champion in the event, two heats to nil.

Wiasak qualified second fastest in the pursuit behind British rider Elinor Barker, but beat her by more than two seconds in their final.

Davison's win in the six-discipline omnium event means Australia leads the medal tally in Mexico with four golds ahead of the final day's events.

Australia opened the cup round on Friday with a gold medal in the men's team pursuit.