Fran Halsall today admitted she was "physically and emotionally" drained by Britain's disaster in the 4x200 metres freestyle relay.

The 18-year-old was part of the under-strength women's quartet which failed to qualify for today's final despite being strongly tipped for a medal.

Halsall, 18, was chosen ahead of Caitlin McClatchey, who has a much faster personal best at the distance, while 400m freestyle golden girl Rebecca Adlington was also rested.

The final was won by Australia in a world record time of 7 mins 44.31 secs with China and the United States taking the other podium spots.

Halsall was back at Beijing's Water Cube this morning and successfully reached the final of the 100m freestyle but said: "After the relay I was physically and emotionally drained. It was really hard because it was a good chance of a gold medal for the team.

"We had two excellent girls to come back in and fill spots and I thought I had to get up this morning and make a final for those girls. I did that and hopefully they can take some inspiration from it.

"I have got a night off so I can get focused for the final tomorrow."

Halsall's time was slower than in her heat but she still finished third in her semi-final to qualify fifth overall.

Liam Tancock led greatest Olympian Michael Phelps for three lengths in the semi-final of the men's 200m individual medley but badly faded in the freestyle to finish fourth.

Still, he qualified for the final along with team-mate James Goddard who came home in third in the second semi.

Phelps is favourite for the event which would mean a sixth gold of the Games and a 12th overall, but surprisingly he was not the fastest qualifier - fellow American Ryan Lochte won his semi in a time 0.01 secs quicker.

Phelps said: "I think medals are more important than times so that's what I am focusing on. It's all about getting as much rest as I can. That's going to be the key."

Lochte was also in action in the 200m backstroke semi-finals and qualified ahead of Britain's Gregor Tait, who finished fourth and made it through to his second straight Olympic final.

Elsewhere in the pool, Japan's Kosuke Kitajima underlined his status as the greatest breaststroke swimmer of all time by winning a second gold.

The 25-year-old added the 200m to the 100m Olympic title he won earlier in the week as he successfully defended the two golds he claimed in Athens four years ago.

Meanwhile, Holland's Pieter van den Hoogenband's bid to become the first male swimmer to win three consecutive Olympic titles came to an end when France's Alain Bernard won the 100m freestyle.