OK, Jason Kenny, here we go...

The reigning Olympic champion against the world champion, Kenny tucks in behind and will have to go for it as the bell rings, the British rider looks to squeeze round the outside but Harrie Lavreysen just holds him off and it's the Dutchman who wins it.

Kenny still has a chance but needs to win the next two races in this best-of-three tussle.

Paula Radcliffe
Women's marathon world record holder on BBC TV

Tom Bosworth looks as though he has dropped off the back of the pack, and it looks like Callum Wilkinson has just had a yellow warning.

Jill Douglas, at the velodrome in Izu for the BBC, reports that Dutch rider Laurine van Riessen - who collided with Katy Marchant in the women's keirin quarter-final - has been taken to hospital.

It is understood that Van Riessen was knocked out, but was conscious as she was taken away on a stretcher.

It's all coming thick and fast at the Izu Velodrome. Jason Kenny is in quarter-final action and he faces current world champion Harrie Lavreysen of the Netherlands.

Chris Boardman
Olympic cycling champion on BBC TV

Matt Walls was very impressive. He looked like he was in trouble, but he instantly got onto a counter attack and picked up some points, he finished third.

Into the final lap.

Who'll take the tempo race? It is Jan Willem Schip of the Netherlands, with Benjamin Thomas of France and Great Britain's Matt Walls behind him.

Elia Viviani, Kenny de Ketele, Niklas Larsen and Benjamin Thomas have also nabbed 20 points after gaining a lap, but Matt Walls has countered and earned the same windfall.

He's up the top of the leaderboard with Thomas and Thery Schir.

Chris Boardman
Olympic cycling champion on BBC TV

This event is relentless.

They're sprinting every 16 seconds - it's absolutely brutal. France's Thomas is the one that's going to close this one down with 27 laps to go.

Matt Walls has decided that the pace of the race is so high that there's not going to be an out and out attack, so he's going to try and gain some points.

Matt Walls is caught up in the pack as Benjamin Thomas of France takes hold in a leading group that are hoovering up the points.

Steve Cram
Athletics commentator on BBC TV

We think Tom Bosworth is on a yellow warning but it is difficult to see when they are still in a pack like this

Amid all the madness on at the cycling velodrome, China's 14-year-old Quan Hongchan was in the diving pool winning the battle of the teenagers against team-mate Chen Yuxi, 15, to take gold.

Bronze went to Australia's Melissa Wu - who at 29 wins her first Olympic medal since Synchro silver in Beijing back in 2008 when Quan was only 18 months old.

Britain's Andrea Spendolini-Sirieix and Lois Toulson finished seventh and ninth respectively.

Image source, Getty Images

Next up in the men's omnium is the tempo race. Matt Walls finished first in the opening scratch race and now pinches a point as he crosses the line first in the second event, with 30 laps to go...

Chris Boardman
Olympic cycling champion on BBC TV

It was a good ride by the Frenchman Vigier. Webster kept control but used a lot of energy to do so and paid the price in the final quarter of the lap.

Team GB race walker Tom Bosworth caused a touch of controversy last week when he said the base for athletes in Sapporo "feels like prison" and the food being served up was "cold slop", though yesterday he apologised if his comments had caused offence.

It is finally race day for the 31-year-old, who finished sixth in Rio and will be taking on the 20km course in Sapporo.

The race has been moved to the city 800km north of Tokyo, which is located on Hokkaido - the second largest of Japan's many islands - and hosted the 1972 Winter Olympics.

It's still 30 degrees, however, should be a walk in the park...

Dame Jessica Ennis-Hill
London 2012 Olympic heptathlon champion on BBC Radio 5 Live

This is sport - it's so fragile you can be at the top of your game on the world stage and in an instant it's snatched away from you.

For athletes like Katarina Johnson-Thompson and Dina Asher Smith they had fantastic 2019 seasons picking up medals, in that sense they were ready - you go into the winter season in fantastic shape you just have to maintain that level of training and then before you know it it's the 2020 Olympics but that changed for everyone.

A whole athlete's world is designed around structure and knowing where those fixed points of competition are and when that changes it can have a massive impact on you physically and mentally.

An update from Katarina Johnson-Thompson, whose heptathlon medal hopes were ended by a calf injury in the 200m yesterday...

Sir Chris Hoy
Six-time Olympic cycling champion on BBC TV

Great ride from Kenny. He's such a smart rider, he really pushed on there, he had the legs.

He got to the front, controlled the race and imposed his tactics. Relatively comfortable.

Jason Kenny is straight back at it and takes charge of the repechage this time to see off Azizulhasni Awang of Malaysia and Japan's Yuta Wakimoto to make it through!

One race more than he'd have liked, but the Brit is into the quarter-finals.

Jason Kenny was beaten by Russian Denis Dmitriev earlier but has another chance to progress in the repechage.

Tom: Think track cycling need to rethink punishments, relegating to the back for crossing a line but a chance to compete for gold if you cause a major crash.

Neale: The cyclists are tough, they come off yet can’t wait to get back on the bike the next day.

Richard: Wow. Marchant absolutely taken out. It looked like a cynical foul to stop a Premier League counter attack. I'm not a rules expert but surely that can't stand?