But the 27-year-old from Hay-On-Wye had to wait for confirmation as the US team lodged an appeal about her equipment.

The US appeal was initially upheld but a GB team counter-appeal succeeded, leaving Pearson as champion.

Posting on Twitter, Pearson said:  ”Unfortunately some people just can’t be gracious in defeat. THE BEST ATHLETE WON fair and square! But this experience has made me stronger and I will bounce back as an even better athlete!”

Pearson’s gold was one of four medals for the GB team with silvers forDan Greaves (F44 discus) and Libby Clegg (upgraded from bronze in the T12 200m after the disqualification of a rival), and bronze for Kyron Duke (F41 shot).

Clegg finished third in the sprint for visually impaired athletes, but was promoted after the China’s Guohua Zhou was disqualified.

There was also an outstanding performance from Brazil’s Alan Oliveirain the T43 200m as he won in 20.76 seconds, beating Oscar Pistorius’s world record of 21.30.

The double amputee, who is set to be the poster boy of the Rio Paralympics, famously defeated Pistorius over 200m at the London Games, and he celebrated this win by proposing live to his girlfriend on Brazilian television.

“I’ve been training hard to run below 21 seconds and I’ve managed it,” he told BBC Sport. “I’m training even harder and pushing myself.

“This year shows how good and how fast and how strong I am. I’m delighted to show that to the world and ready to win the 100m. I’m pretty sure that if Oscar was here I would have beat him anyway.”

Earlier in the field events, Pearson’s gold medal was in jeopardy after the American team claimed she had used an illegal substance on her hand during the competition, and that the discus she used was not available to other competitors.

“Josie has used the substance, which she is entitled to do, for the last 18 months, including in London,” explained GB head coach Paula Dunn.

“Thankfully the panel saw sense but it has been a very stressful time. I think it shows bad sportsmanship but we now have to move on and not let it overshadow the great performance she put in.”

Pearson, who broke her back in a car accident in 2003, played wheelchair rugby for GB at the Beijing Paralympics and competed in track racing at the last World Championships in New Zealand two years ago.

But she has found her niche in the throwing events and will also compete in the club throw on Wednesday.

After her competition and before the controversy erupted, she told BBC Sport that she knew a world record was on the cards in Lyon

“I knew I could do it under the right conditions,” she said.

“You don’t take anything for granted going into any competition but I knew I had done a good winter’s training after London and had prepared well.

“I had about six weeks off after London but then you get itchy feet and I wanted to get back into training because I knew the Worlds were coming up this year and I love competing,” she said.

Her fellow thrower Greaves saw his world T44 discus title taken by American rival Jeremy Campbell.

The Briton struggled for consistency and could only manage 54.58m, with Campbell throwing a best of 58.86.

Some of the other British highlights included a championship record for 16-year-old Sophie Hahn in the semi-finals of the T38 200m, while fellow teenager Olivia Breen also advanced to the final.

Newcomer Lee Whiteley (T38 100m), Bethy Woodward and Katrina Hart (T37 200m), and Graeme Ballard and Ben Rushgrove (T36 100m) were also among those to advance to their finals.

BBC

The IPC World Athletics Championships in Lyon, France, is the biggest event for the world’s best track and field athletes since last year’s sell-out Paralympics in London.  BBC Sport will have coverage across radio, television and online for the competition, which begins on Saturday 20 July

Here is a guide to the main athletes chasing success on each day of the event.

Day One – Saturday 20 July

Defending World Champion Nathan Stephens will compete in the F57/58 javelin final on the opening morning

Defending World Champion from 2011 Nathan Stephens is first up in the F57/58 javelin final on the opening morning.

Later, double World and Paralympic champion Hannah Cockcroft goes in the final of the women’s T34 200m while Welshman Aled Davies – the discus champion from last year, will compete in the shot put final.

There’s also a chance for a first look at sprinters Libby Clegg and Ireland’s Jason Smyth in their 200m events while Brazil’s Alan Oliveira goes over the same distance. Oliveira is the man who famously beat Oscar Pistorius to gold last summer.

Day Two – Sunday 21 July

Britain’s Paralympic discus champion and former wheelchair rugby player Josie Pearson is the highlight of the morning action on day two while Bethany Woodward, Katrina Hart and Jenny McLoughlin will bid to advance to the T37 200m final.

Britain’s Paralympic discus champion and former wheelchair rugby player Josie Pearson is in action on day two

There is a great duel expected in the evening session with Dan Greaves hoping to defend his F44 world discus title against Paralympic champion and world record holder Jeremy Campbell from America.

Brazil’s Alan Oliviera (T44 200m), Libby Clegg (T12 200m) and Jason Smyth (T13 200m) will all be hoping to win medals in their respective events while Northern Ireland’s Michael McKillop builds for success in the T37 800m and British wheelchair racers Shelly Woods and Jade Jones go in the T54 5,000m.

Day Three – Monday 22 July

Paralympic champion Richard Whitehead will begin the defence of his world T42 200m title on day three

Paralympic champions Richard Whitehead and Jonnie Peacock both get their World Championship campaigns underway in Lyon.

Whitehead starts the defence of his world T42 200m title while Peacock will hope to lay down a marker to the rest of the field including Richard Browne and defending world champion Jerome Singleton in the T44 100m semi-finals.

Hannah Cockcroft goes in the final of the T34 100m while Sophia Warner (T35 100m), Olivia Breen (T38 100m) and Bethany Woodward and Katrina Hart (T37 100m) will be among those Britons chasing medals.

Day Four – Tuesday 23 July

Paralympic F42 discus gold medallist Aled Davies will be hoping to add the world title to his list of honours on day four

Wales’s Aled Davies won gold in the F42 discus at last summer’s Paralympics and he will hope to add the World title to his list of honours on Tuesday morning in Lyon while Libby Clegg will start the defence of her T12 100m title.

Richard Whitehead and Jonnie Peacock will hope to figure in their respective finals – the T42 200m and T44 100m.

Stef Reid will be bidding to leap her way to a medal in the T44 long jump while wheelchair racer Mickey Bushell goes in the semi-finals of the T53 200m while major championship debutant Lee Whiteley will be hoping to reach the T38 200m

Day Five – Wednesday 24 July

Northern Ireland’s Michael McKillop will be in action in the T37/38 1500m on day five

Teenager Sophie Kamlish and former Wales hockey player turned sprinter Laura Sugar will be in action in the morning in their T44 100m semi-finals.

The likes of Graeme Ballard and Ben Rushgrove (T36 200m), Libby Clegg (T12 100m), Ola Abidogun (T46 100m) and Bethany Woodward and Katrina Hart (T37 100m) will hope to figure in their respective finals.

Also on the track, Northern Ireland’s Michael McKillop will be hoping to take gold in the T37/38 1500m while Paul Blake goes in the T36 1500m.

Day Six – Thursday 25 July

Paralympic champion Mickey Bushell will begin his campaign to win gold in the 100m on day six

Paralympic champion Mickey Bushell will hope to better the world 100m silver medal he won in Christchurch two years ago when he starts his campaign in the event.

Stephen Miller, who had a hip operation after London, will be hoping to show he is back to full fitness in his club throw event while teenager Scott Jones makes his major international debut in the F34 shot and Scott Moorhouse goes in the F42 javelin.

On the track American ace Tatyana McFadden will be hoping to impress in the T54 1500m final while Northern Ireland’s Jason Smyth (T13 100m) and GB duo Sophie Kamlish and Laura Sugar (T44 100m) will be hoping to figure in their finals

Day Seven – Friday 26 July

American amputee athlete David Prince takes to the track in the T44 400m on day seven

Discus thrower Bev Jones gets things underway for the British team on Friday morning as she bids to add to the Paralympic bronze she won last year.

Mickey Bushell will be expecting to challenge for gold in the T53 100m final while Paul Blake is hoping to go one better than he did in London, where he won silver, when he competed in the T36 100m.

American amputee athlete David Prince, who set a new 400m world record in his T44 category recently, will hope to claim the world title.

Day Eight – Saturday 27 July

Bethany Woodward will defend her T37 400m title on day eight

Throwers Robin Womack and Kieran Tscherniawsky go in the shot and discus respectively while Bethany Woodward will defend her T37 400m title and Laura Sugar and Sophie Kamlish go in the T44 200m final.

Jade Jones will hope to figure in the T54 final on the final evening of action in Lyon where she is set to come up against American star Tatyana McFadden and her younger sister Hannah.

GB squad newcomer Erin McBride finally gets her chance to get on track in the T13 400m final

Day Nine – Sunday 28 July

On the final day of action in Lyon, the spotlight will be on Shelly Woods who will be aiming to go one better than the silver medal she won at the Paralympic marathon. Woods is the only GB athlete competing in the marathons.