Take a look at all the action coming up on the third day of the London 2012 Olympics.
Leisel and Leiston take on Soni
As world champion and world record holder in the 100m breaststroke, Leisel Jones went into Beijing four years ago as the hottest of favourites for the gold medal.
The expectations on her were balanced by the fact that she had never won an individual gold medal in two Olympic Games prior to Beijing.
In the end, Jones did break her duck, beating American swimmer Rebecca Soni and Austria’s Mirna Jukic for the Olympic title.
Since then, however, the pendulum has swung clearly in favour of the American. Soni blitzed Jones in the 200 metre breaststroke in Beijing, and since then has largely had the wood over the Australian.
At the Australian relay camp leading into this year’s Olympics, Jones said that she was looking forward to being the “hunter, not the hunted” in London. But the task facing her still remains difficult, to say the least.
On the rankings the biggest threat to Soni is from her own team-mate, Breeja Larson, whose time at the US Olympic Trials was just 0.1 of a second outside Soni’s.
Japan's Satomi Suzuki is next fastest, nearly a second back from Soni, while the best-placed Australian is not Jones, but Leiston Pickett, the 20-year-old Queenslander.
If Jones is to have a chance of defending her title, she needs to make up close to a second and a half on her time from the Olympic trials in Adelaide – that’s not impossible, but at this stage there's a much greater chance of hearing The Star-Spangled Banner at the victory ceremony than Advance Australia Fair.
Meanwhile, Emily Seebohm will be the heavy favourite to take gold in the women's 100m backstroke final.
She will start in the middle lane after recording the fastest semi time of 58.39 seconds.
Seebohm enjoyed a commanding lead early in her semi-final and came close to challenging world-record time before finishing comfortably in front of China's Zhao Jing and Russia's Anastasia Zueva.
Fellow Australian Belinda Hocking also snuck in to the final in seventh place overall with a time of 59.79 seconds.
Tough ask for Fraser-Holmes
This event could have been round two in the Michael Phelps - Ryan Lochte battle, but instead it seems likely to be the confirmation of Lochte's crowning as the new king of the pool.
Lochte, who vowed never to come second again after playing second fiddle to the Phelps juggernaut, has come back exhibiting two elements of the Olympic motto.
On the basis of night one at the Aquatic Centre, he is clearly stronger and faster than he was four years ago.
And, of course, if his triumph in the 400 metres individual medley does prove to be a springboard to a multiple gold medal haul in the pool, then the 27-year-old will definitely be higher in terms of his ranking as an all-time Olympic swimmer.
The four-lap freestyle event will not be easy for the American, however.
Yannick Agnel stopped the clock at 1 minute 44.42 seconds at the French championships in March - a time more than a second faster than either Lochte or Phelps have achieved in 2012.
Lochte went inside his season's best time in the 400 IM by nearly two seconds in the final, however, so if he can maintain that level of improvement, Agnel will be under threat.
Phelps will not compete in this event, with Lochte's American competition coming from Ricky Berens, who was part of the United States' gold medal-winning 4x200 metre freestyle relay team in Beijing.
Kosuke Yagino from Japan, who came third in the 400 IM final, will challenge for the medals.
Flying the Australian flag will be Thomas Fraser-Holmes and Kenrick Monk. Monk will have extra incentive to after his fateful Facebook posting of him in a gun shop with Nick D'Arcy was punished by the AOC, who decreed the pair would be sent home following their events.
Both men will struggle to challenge the favourites in this event. Fraser-Holmes' seasons-best is 2.46 seconds outside Agnel's, while Monk's best is 2.74 seconds shy of the Frenchman.