British cyclist Matt Walls was crowned Olympic champion on his debut with a dominant performance in the omnium.

The 23-year-old finished on a total of 153 points, 24 more than silver medallist Campbell Stewart of New Zealand, while Italy's defending champion Elia Viviani took bronze.

His victory earns Team GB's first track cycling gold medal at the Tokyo Games.

Walls adds an Olympic medal to his world championship bronze and European title in the event.

"I managed to get a good lead coming into the end. It's been a hard day but I came into that points race with a bit of a lead and breathing room," he told BBC Sport.

"Thank you to all my family and friends. I wouldn't be here without them, especially my parents."

Walls' medal was Team GB's 50th of the Tokyo Olympics, and the 16th gold.

Oldham's Walls is Great Britain's first male Olympic champion in the omnium, after Mark Cavendish's silver at Rio 2016 and Ed Clancy's bronze at London 2012 - when the event was first included on the Olympic programme.

Laura Kenny is the two-time defending champion in the women's event, which takes place on Sunday.

Elsewhere on Wednesday, Jack Carlin reached the sprint semi-finals but two-time defending champion Jason Kenny is out.

Kenny was beaten in the quarter-finals by Dutch world champion Harrie Lavreysen, ending his nine-year reign.

Katy Marchant saw her keirin campaign cut short in the quarter-finals after she was caught up in a crash.
Wonder Walls wins gold

Walls got his campaign at the Izu Velodrome off to the perfect start when won the opening scratch race, before placing third in the tempo race.

Second place followed in the elimination race, ensuring he would top the overall standings going into the 100-lap points race.

He was one of several riders to gain a lap early on, earning 20 points, and won two of the sprints.

Stewart earned two laps to catapult him on to the podium, having been in seventh after three of the four disciplines.

Walls had tested positive for Covid-19 in March, disrupting his road season with his team Bora-Hansgrohe, before returning to competitive action in June.

Britain's track cyclists have now won three medals at Tokyo 2020, following silvers in the women's team pursuit and men's team sprint.

Kenny exits as Carlin impresses

After Wednesday's early rounds in the men's sprint, Kenny - an eight-time Olympic medallist - said his younger team-mate Carlin was Team GB's best chance of a medal in the event.

Kenny, 33, said he was "struggling a bit" after his efforts to win team sprint silver alongside Carlin and Ryan Owens earlier in the week.

That fatigue was evident on Thursday as he was beaten by Denis Dmitriev of the Russian Olympic Committee in the 1/8 finals, and was forced to go through the repechage to reach the last eight.

That extra race counted against him as he faced 24-year-old Lavreysen, the two-time sprint world champion winning over two legs.

"It isn't [a disappointing result]," said Kenny, who will look to retain his keirin title over the weekend. "I don't expect to be the best in the world all the time. It is really hard to win, at the end of the day.

"I gave it my best shot, and I just wasn't good enough.

"For whatever reason, I wasn't as good as I wanted to be physically, and these boys are just better."

But there was no such issue for 24-year-old Scot Carlin, who continued his impressive form into a second day after breaking the Olympic record in qualifying - though it was then broken by Lavreysen and Dutch team-mate Jeffrey Hoogland.

Carlin comfortably defeated Germany's three-time Olympic medallist Maximilian Levy in the quarters, to set up a last-four race with Lavreysen.

"Another day in the bag, we'll see what happens tomorrow," Carlin told BBC Sport. "The legs are feeling good."

On team-mate Kenny, he added: "Jason was struggling - fatigue kicked in from the team sprint but he still went out and gave it his all and that's what Olympic champions do."
Marchant out after crash

Marchant had looked in promising form in the women's keirin but her hopes of a medal were ended prematurely.

Dutch rider Laurine van Riessen appeared to clip a wheel and lost control of her bike, ploughing into Marchant's wheel and bringing them both down.

Marchant was able to get up quickly but Van Riessen - also a Winter Olympic medal-winning speed skater - was taken to hospital.

"I think that's just bike racing - wrong place, wrong time," Marchant, 28, told BBC Sport.

"I hope everyone's all right that was in the crash. I think I'm all right, just a bit battered and bruised."

Marchant will return to the track on Friday in the individual sprint, the event in which she won bronze at Rio 2016.