SWIMMING: Australia's swimmers are off to a flying start in Beijing, winning four gold, four silver and two bronze medals on the first day of the World Cup meet.

World champions Emily Seebohm and Cate Campbell were joined on the top of the podium by teammates Ashley Delaney and Dan Smith.

Seebohm, who won Olympic gold in the 4x100m medley relay at the same venue in 2008, kept her high-profile rivals Hungarian Katinka Hosszu and Olympic champion Missy Franklin at bay, winning the 200m backstroke in 2:09.22.

She powered home over the final 50 metres after Franklin had led through the first 150 metres.

Earlier, Seebohm (27.68) finished second to China's Fu Yuanhui (27.55) in the 50m backstroke.

The Campbell sisters were also in action with Cate following on from her recent Singapore victory over world champion sibling Bronte in another thrilling 50m freestyle final.

Cate clocked 24.30 to Bronte's 24.53.

"It is a tough competition," Cate Campbell said. "The Chinese swimmers were very fast in the morning so I knew I had to be faster in the final, especially against Bronte who is always very tough."

London Olympic backstroker Delaney continued his strong World Cup form, winning gold in the 100m in 54.36, edging out Japan's Yuki Shirai (54.71) with Britain's Marco Loughran third in 55.96.

Smith chalked up his fourth World Cup win of the circuit in the 400m freestyle, adding to his victories over 200m in Paris and the 200m and 400m freestyle double in Singapore.

Smith, a member of Australia's bronze-winning 4x200m freestyle relay team at the world championships, won in 3:51.45 from Austria's David Brandl (3:51.61) and Australian Jacob Hansford (3:51.62).

In the 400m individual medley Sydney pair Tomas Elliott and Kazimir Boskovic continued their solid World Cup form, finishing with silver and bronze in the 400m individual medley final.

AAP