Allyson Felix will target a record 10th Olympic athletics medal in the women's 400m, while Sifan Hassan of the Netherlands can complete the second leg of an unprecedented treble in Tokyo with gold in the 1500m final Friday.

The 35-year-old Felix, running in her fifth and final Olympics, is bidding to become the most decorated female track and field athlete in Games history.

She is currently level with Jamaican legend Merlene Ottey on nine Olympic medals, and took silver in the 400m five years ago in Rio.

"It was a fight to get here. When I was younger, I never really thought about making a final," said Felix, who is also set to run in the 4x400m relay on Saturday.

"This time, you get older and it seems harder. You just have to get smarter and figure it out."

The Ethiopia-born Hassan, already a gold medallist in the 5,000m in Japan, goes up against Kenya's defending champion Faith Kipyegon in the final of the shortest of her chosen three disciplines.

US track star Allyson Felix is competing at her fifth and final Olympics
US track star Allyson Felix is competing at her fifth and final Olympics AFP / Jewel SAMAD

Hassan is also eyeing the 10,000m in an unprecedented tilt at middle-distance dominance.

With two-time winner Mo Farah failing to make the British team, a new Olympic champion will be crowned in the men's 5,000m, where Joshua Cheptegei headlines a strong trio of Ugandans including Jacob Kiplimo and Oscar Chelimo.

Jamaica look runaway favourites for the women's 4x100m relay, led by double sprint champion Elaine Thompson-Herah and 100m silver medallist Shelly-Ann Fraser-Pryce.

The American men failed to qualify for the men's 4x100m final after trailing home sixth in their heat, a performance branded a "total embarrassment" by Carl Lewis.

After gold in the mixed 4x400m relay and two more in the hammer, Maria Andrejczyk hopes to give Poland another in the women's javelin.

Warm temperatures again await the field in the men's 50km and women's 20km race walk finals, held in the northern city of Sapporo to avoid Tokyo's searing summer heat.

Top-ranked Nelly Korda leads by four shots after two rounds of the women's golf tournament
Top-ranked Nelly Korda leads by four shots after two rounds of the women's golf tournament AFP / YOSHI IWAMOTO

China sit atop the medals table with 34 golds, and will expect to add to their tally in the table tennis men's team final against Germany.

Dutch cyclist Harrie Lavreysen is aiming to succeed Jason Kenny as the new men's sprint champion after knocking the two-time gold medallist out in the quarter-finals.

Laura Kenny, who owns the most gold medals of any British female athlete ever, lines up in the women's madison, included on the Games programme for the first time.

Sweden, the 2016 runners-up, take on first-time finalists Canada in the women's football final in Yokohama.

The match, initially scheduled for 11am, was relocated from Tokyo's Olympic Stadium and pushed back until the evening because of heat concerns.

Hosts Japan play Mexico in the men's bronze medal match in Saitama.

World number one Nelly Korda holds a four-stroke lead going into the third round of the women's golf tournament, which could be shortened to 54 holes due to the threat of an approaching tropical storm system.

The Netherlands will bid for a record fourth Olympic women's hockey title against Argentina, while the United States face Serbia for a spot in the women's basketball final.

In karate, three-time world champion Ryo Kiyuna of Japan is vying to become the first Olympic gold medallist in the men's kata event.

There are also gold medals up for grabs in beach volleyball, women's sport climbing, modern pentathlon, wrestling and boxing.