Kazan: Australia achieved two unique doubles at Kazan`s world swimming championships on Friday as Mitchell Larkin claimed another backstroke title and the Campbell sisters took 100m freestyle gold and bronze.
Larkin, 22, is the first Australian to win both the 100 and 200m backstroke titles at a world championships.
Compatriot Emily Seebohm can match him on Saturday in the women`s 200m backstroke final having already claimed the 100m world title on Tuesday.
Larkin clocked 1min 53.58sec to claim his gold after a strong surge over the last 50m while Poland`s Radoslow Kawecki took silver, 0.97sec back, as Russia`s Evgeny Rylov earned bronze at 1.02.
It is a decade since there was a double men`s backstroke world champion after Aaron Piersol of the USA won both events in Montreal in 2005.
"I have achieved some of the greatest dreams of mine since I was a kid," said Queensland-born Larkin.
"To be a world champion is one thing, but to be a double champion is amazing."
Larkin admitted he was inspired by Australia`s two medals in the women`s 100m freestyle final just before his race after Bronte Campbell kept it in the family by succeeding older sister Cate as world champion.
It is the first time sisters have made the podium at a world swimming championships in an individual event, but the Campbells had already stood on the dais together in Kazan after Australia won the 4x100m freestyle relay last Sunday.
Bronte clocked 52.52 seconds to win the 100m title with Sweden`s Sarah Sjostrom taking silver at 0.18sec back as Cate earned bronze at 0.30."It was unbelievable. Me and my big sister were standing up there on the podium singing the national anthem together," said the 21-year-old Bronte.
"It was great to be able to share the moment with her.
Britain claimed their fifth gold medal in the Kazan pool in the men`s 4x200m freestyle relay thanks to a superb anchor leg from individual champion James Guy.
The 19-year-old, who won the 200m freestyle world title on Tuesday, took the British quartet from third to first to win on the wall.
He touched at seven minutes, 04.33 seconds as the United States took silver at 0.42secs while Australia earned bronze at 1.01.
Hungary`s Daniel Gyurta was denied an historic fourth straight 200m breaststroke title as Germany`s new champion Marco Koch came within 0.75 of the world record to claim gold.
Koch clocked two minutes, 07.76 seconds as Kevin Cordes of the United States earned silver at 0.29secs while Gyurta had to settle for bronze at 0.34.
Had Gyurta won, the Olympic champion would have joined Ryan Lochte, in the 200m individual medley, and Grant Hackett, in the 1500m, as the only swimmers to have claimed a fourth straight gold in a single world championship event.
There was a bizarre twist in the women`s 200m breaststroke final as three swimmers were awarded bronze as Japanese teenager Kanako Watanabe won the gold to claim her second medal in Kazan.
Watanabe, 18, clocked two minutes, 21.15 seconds with Micah Lawrence of the United States taking silver at 1.29 back.
But Spain`s Jessica Vall, Denmark`s world record-holder Rikke Moller Pedersen and China`s Shi Jinglin all swam 2:22.76 in a three-way split for third.
It was the second gold for Japanese women in the Kazan pool in as many days after Natsumi Hoshi claimed a surprise victory in the 200m butterfly on Thursday.
Hungary`s Katinka Hosszu is the fastest through to the women`s 200m backstroke final on Saturday after clocking 2:06.18 with Seebohm just behind in 0.38secs.
World record-holder Missy Franklin of the USA was third fastest at 1.61secs behind as she chases her first gold in Kazan.
Nathan Adrian of the USA was the fastest into the men`s 50m freestyle final on Saturday, but the Olympic 100m champion faces a battle royal as France`s Florent Manaudou was just 0.04secs behind him.
Chad Le Clos of South Africa, Tom Shields of the USA and Hungary`s Laszlo Cseh are all in the mix for a 100m butterfly medal on Saturday.
Shields and Cesh, who won the 200m gold on Wednesday, both clocked 51.03secs to win their respective semi-finals, while Le Clos was just 0.08secs back.