Ethiopia's Selemon Barega secured gold in the men's 10,000 metres final as the athletics got underway at the Tokyo Olympics on Friday.

Barega surged clear of Joshua Cheptegei and Jacob Kiplimo, who were each denied a first Olympic gold for Uganda, as he clocked 27 minutes 43.22 seconds in the Japanese capital.

Cheptegei, the 2019 world champion, was highly fancied to win, while compatriot Kiplimo would have become the youngest man to be crowned champion at the distance at the age of 20 years and 258 days.

But Barega, himself only 21, claimed the honour of the maiden athletics gold at this year's event after timing his kick for the line to perfection.

USA SUFFER MIXED RELAY DQ

It was a disappointing outing for the United States' mixed 4x400m relay team as the favourites were disqualified.

The event is making its debut in the Olympics but the landmark will not be fondly remembered by USA's foursome after one of their baton exchanges was deemed to have taken place outside the designated zone.

That has left the gold medal well and truly up for grabs, with Belgium, Ireland and Germany the automatic qualifiers from heat one, while in heat two it was Poland, Netherlands and Jamaica.

Great Britain and Spain round off the final eight, having gained the two next best times.

HASSAN SETS THE STANDARD

Dutchwoman Sifan Hassan laid down a marker in the heats for the 5,000m.

The first heat was much quicker than the second, with Hassan's 14:47.89 leading the way.

She is chasing a first Olympic medal and will face stiff competition from the likes of Kenya's Hellen Obiri.

Obiri won silver in Rio and qualified second fastest in the second heat with a time of 14:55.77.

HAVING A FIELD DAY

In two of the field events to begin on Friday, women's world number one triple jumper Yulimar Rojas recorded the longest leap of the heats at 14.77m.

The Venezuelan, a two-time world champion, had to settle for silver in Rio behind Colombia's Caterina Ibarguen, who will be eyeing a repeat in Tokyo.

Ibarguen's qualifying jump was a season's best 14.37m.

China led the way in the women's shot put, Gong Lijiao staking her claim with a throw of 19.46m, putting her ahead of compatriot Song Jiayun (19.23).