Iron Lady's 3rd in a row

Hungary's Katinka Hosszu snared her third gold medal at the Rio Olympics on Tuesday with a gut-busting win in the women's 200m individual medley final.

The 27-year-old led from start to finish to win the gruelling multi-stroke event in a time of two minutes 06.58 seconds, just 0.46 outside the world record she set at last year's world championships in Russia.

Britain's Siobhan-Marie O'Connor took the silver in 2:06.88while the bronze medal went to American Maya DiRado in 2:08.79.

Known as the "Iron Lady" of swimming, Hosszu is vying with Michael Phelps and Katie Ledecky as one of the stars in swimming at Rio.

She also broke the world record in the 400 medley in Rio and was a surprise winner of the 100m backstroke, joining an elite group of female swimmers to have won three individual gold medals at a single Olympics.

Hosszu had entered a mind-boggling five events in Rio but withdrew from the heats of 200m butterfly earlier Tuesday, leaving her with four.

If she wins her final event, the 200m backstroke, she will equal the all-time record for a female swimmer in individual events at a single Games, set by East Germany's Kristin Otto in Seoul in 1988.

United States star Katie Ledecky bagged her second gold medal of the Olympic Games after powering to victory in the women's 200m freestyle.

Ledecky, who shattered the 400m freestyle world record in winning gold on Sunday, was second at the 100m mark but had moved into first at the final turn, holding off Sweden's Sarah Sjostrom with Australia's Emma McKeon claiming bronze.

Ledecky touched in 1min 53.73sec and is two-thirds of the way to a rare treble.

She can become the first Olympian since Debbie Meyer in Mexico City in 1968 to sweep the 200m, 400m and 800m freestyles.

The 19-year-old from suburban Washington DC burst onto the international scene with her 800m free triumph in London four years ago.

But she admitted the 200m is her toughest challenge, and Tuesday's race was no exception, but she held on against a determined Sjostrom -- who came into the race buoyed by her own world record-setting win in the 100m butterfly on Sunday.

Sjostrom, whose fly win made her the first Swedish woman to win Olympic swimming gold, was delighted with silver.