Olympic champion Kirani James produced a hot performance in cold weather on Friday when he clocked the fastest time of the year to win the 400 metres at the Drake Relays in Iowa.

The 23-year-old Grenadian showed he was on track to defend his title in Rio in August by clocking 44.08 seconds in swirling winds at the meeting in Des Moines.

In a battle between the last two Olympic champions, James beat American LaShawn Merritt by 0.14 seconds.

James' time was not far off the 43.94 he ran to win in London four years ago, when he made history as the first ever Olympic champion from the tiny Caribbean island nation of barely 100,000 people.

That time remains his personal best.

"It just shows that I'm on a great track to do some great things this year," James said after Friday's race.

The 23-year-old finished third in the 400 at last year's world championships in Beijing behind South African Wayde van Niekerk.

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