Hayes (right) produced a good run to finish second in Mooloolaba
British triathletes Stuart Hayes and Liz Blatchford finished second and third in their respective opening World Cup events of the year in Australia.
Hayes completed the 1.5km swim, 40km ride and 10km run 10 seconds slower than Australian Brad Kahlefeldt, who won in one hour 51 minutes, 41 seconds.
The Czech Republic's Vendula Frintova won the women's race in 2:03.15, ahead of Japan's Tomoko Sakimoto.
Blatchford finished in 2:03.43 while fellow Brit Jodie Stimpson was sixth.
The World Cup is a second-tier event behind the World Championship series, which begins in the same country, in Sydney, in two weeks' time.
There, Blatchford and Stimpson will join British team-mates Helen Jenkins and Vicky Holland.
Leading British men's triathlete Alistair Brownlee, who won last year's World Championship title, is expected to be out until July with a stress fracture.
"I sat in the big pack on the bike to wait for the run," said Hayes after the Mooloolaba race.
"My first five kilometres was tough but I found my legs in the last half."
Blatchford said of her bronze: "I felt good through about seven kilometres of the run, but after that I couldn't make any more moves.
"The last three kilometres was just survival for me, just to get around the course."