New Zealand great Jonah Lomu will be remembered for "changing rugby union", says former England head coach Sir Clive Woodward.
Lomu, 40, died on Wednesday at home in Auckland. He had been diagnosed with a rare kidney condition in 1995.
He was capped 63 times for the All Blacks and became a global star after scoring four tries against England in the 1995 World Cup in South Africa.
"He took rugby to a whole new level," Woodward told BBC Radio 4.
"There's very rarely one player who dominates a whole World Cup and he certainly did."
Lomu made his Test debut in 1994 and was only 20 years old when he faced England in the 1995 semi-final in Cape Town.
Standing 6ft 5in (196cm) and weighing 18 stone (119kg), he famously bulldozed several players and ran straight over the top of full-back Mike Catt on his way to one of four tries in the Al Blacks' 45-29 win.
"He was unstoppable," said Woodward, who led England to the World Cup in 2003.
"For the first time ever you had this incredibly gifted, large, very fast athlete on the wing.
"Wingers are usually small and nimble. Suddenly you had this huge guy who was big and fast and amazing. He changed rugby."
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'A freak of nature'
Lomu's prominence at the 1995 World Cup helped him become one of the first superstars of the sport's professional era.
"It was great timing for rugby to enter into the professional era, and Jonah was instrumental after the way he played in that tournament," said former New Zealand team-mate Justin Marshall.
"He was a freak of nature at the time. He was 110kg but could run like the wind.
"Having that on the end of your chain rather than in the forward pack was a revolution of the game."
Lomu scored 37 tries for New Zealand and, despite never winning the World Cup, he is the joint top try-scorer in the competition's history - alongside South Africa wing Bryan Habana - with 15 in 11 games.
"He was very unique but also one of those guys who never had a big head. He knew his ability but he was very humble," former Australia winger David Campese told BBC Radio 5 live.
Former New Zealand All Blacks head coach Graham Henry described Lomu as a "magnet" for rugby who "came from no-where", and said: "He was not so good without the ball, so not perfect, but give him a bit of space and give him the ball - anything could happen."
Ex-South Africa captain Francois Pienaar and Lomu's former New Zealand team-mate Andrew Mehrtens also paid tribute on BBC Radio 5 live.
"He took the game of rugby to the living rooms of people that didn't know about rugby but appreciated that athleticism, skill and power," said Pienaar. "He became the hero of many, many kids, who wanted to emulate him. He was the first truly global rugby superstar on and off the pitch."
Mehrtens described Lomu as "awe inspiring" and "extraordinary".
Tributes to Lomu
Ex-England fly-half Rob Andrew, who played against Lomu in the World Cup in 1995, told BBC Radio 5 live: "He was a blooming nightmare to play against.
"He was intimidating and he had a smile on his face when he did it, which made it even worse.
"We all just chased around after him like kids in the playground. Not many people could single-handily change rugby matches. He was a legend."
Ex-England centre Will Carling told BBC Radio 2: "He was so powerful, explosive and destructive on the pitch, and yet off it he was so gentle and quiet. It was an amazing contrast.
"He demolished England in 1995. I never would have thought he would have taken the game away from us in 20 minutes.
"He's one of those few players who could play in any generation. He could be as much of a superstar now as he was then."
Former England scrum-half Matt Dawson wrote on Twitter: "The greatest rugby player who globalised our game and inspired millions. I'll proudly say to my kids I knew and admired him."
South Africa wing Bryan Habana wrote on Instagram: "His on-field fearlessness was matched by his off-field humility. Our thoughts and prayers go out to his family and friends.
"It was a privilege to have met you, to have been inspired by you and to watch you make the biggest impact we have ever seen on the game we love so dearly."
Former Wales international Jonathan Davies told BBC Sport: "They'd never seen the likes of him before and he brought new supporters to the game of rugby.
"What he achieved on the field was absolutely incredible and he had such a massive impact on the game of rugby. I'm absolutely devastated. It's such a tragic loss at such a young age."
Wasps coach Dai Young, who worked with Lomu at Cardiff Blues, told BBC Sport: "I had the privilege of working with him and not only was he a real rugby legend and role model, he was a real gentleman.
"Everything that's good about rugby - the values and behaviours - he was a man that demonstrated that."
Listen again to BBC Radio 5 live's Jonah Lomu: The Man Who Changed Rugby