Caeleb Dressel and Emma McKeon star on swimming's final day at Tokyo Olympics

American takes tally to five golds while Australian becomes first female swimmer to win seven medals at a single Games

Caeleb Dressel and Emma McKeon starred on swimming's final day at the Tokyo Olympic on Sunday as the American took his tally to five golds and the Australian became the first female swimmer to win seven medals at a single Games.

Dressel earned the title of world's fastest swimmer with a lightning 21.07 seconds in the 50m freestyle before helping the US men shatter their own world record in the 4x100m medley relay.

"I'm proud of myself, I think I reached what my potential was here at these Games and it was just really fun racing," said Dressel.

McKeon was just as impressive, blasting through the 50m to win in 23.81 before spearheading Australia to the women's medley relay honours on the final day of action.

It boosted her medal tally to seven – four gold and three bronze – surpassing the six won by East German Kristin Otto (1952) and American Natalie Coughlin (2008).

McKeon also matched the record for the most decorated female athlete at a single Games, tied with Russian gymnast Maria Gorokhovskaya (1952).

McKeon snared gold in the 50m and 100m freestyle, 4x100m relay and the medley, along with bronze in the 100m butterfly and two further relays.

"It's very surreal now it's over. It all went by very quickly and I'm very happy with how the meet went," she said. "I look at the athletes that have gone before me and have been so impressed and inspired by what they've done but I've never been into the stats and medal counts.

"But to be in that kind of company, it's an honour and I know I've worked hard for it."

Like McKeon, Dressel took out the 50-100 freestyle double, but also powered to the 100m butterfly title in world-record time, while adding 4x100m freestyle and medley relay to place himself in rarified company.

He joins Americans Michael Phelps, Mark Spitz and Matt Biondi, and Otto, as the only swimmers to win five or more golds in one Games.

"I'm giving a pat on the back then put it away and move forward," Dressel said. "I'm going to take a break, I'm pretty over swimming, and enjoy time with my family."

Once again the superpowers dominated the nine-day meet, where six world records fell.

South African Tatjana Schoenmaker joined Dressel with a world record when she crushed the long-standing women's 200m breaststroke best.

New benchmarks were also set in the women's 4x100m relay (Australia), women's 4x200m relay (China), mixed 4x100 relay (Britain) and by the US in Sunday's men's medley.

While the US again topped the medal table with 30, including 11 gold, second-placed Australia made serious inroads.

Among their 20 medals were nine golds – their highest number at an Olympics, and a huge improvement on their three titles in Rio.

In contrast, the US underperformed from their 33 medals and 16 golds in Rio, with Dressel and Katie Ledecky doing the heavy lifting.

Both Dressel and McKeon returned for the event-closing relays with Dressel delivering a storming butterfly leg to steer the US to a world-record 3:26.78.

It crushed their own global mark of 3:27.28 set at the 2009 world championships, with Adam Peaty's Britain taking silver ahead of Italy.

In the women's relay, McKeon swam the fly for Australia, leaving Cate Campbell to bring them home in an Olympic-record 3:51.60 to upset the American two-time defending champions. Canada were third.