Shaun Edwards has likened South Africa dangerman Cheslin Kolbe to England World Cup winner and try machine Jason Robinson.
The 5ft 7in Springboks wing presents a huge threat to Wales in Sunday's World Cup semi-final clash.
He has scored seven tries in 13 Tests and added an extra attacking dimension to South Africa's established physical approach.
"If you want to watch a game of rugby, you want to go and watch Cheslin Kolbe," Wales defence coach Edwards said.
"We will have to keep an eye on him. He is one of the most dynamic players I've ever seen.
"I was lucky enough to play with Jason Robinson for many years. I was his captain at Wigan when he first came in the team there.
"Kolbe is a similar player to Jason – incredibly explosive, short and defies the fact that you have to be big to play the game of rugby.
"Out wide, they (South Africa) have got incredible speed. If there was a 4x100m relay race with all the teams in the World Cup, they would probably be the fastest.
"They have got blowtorch speed on the edges."
Cardiff Blues wing Owen Lane, meanwhile, has been called into Wales's World Cup squad as replacement for injured back-row forward Josh Navidi.
The 21-year-old made his Test debut during Wales's World Cup warm-up games, scoring a try against Ireland in Cardiff.
The Welsh Rugby Union confirmed that Lane will arrive in Japan on Tuesday, with Navidi sidelined for the remainder of the tournament due to a hamstring injury.
For Edwards, Sunday's game will be his second Rugby World Cup semi-final as part of Wales' coaching staff, having seen France edge them out 9-8 in 2011.
"This is where you want to be," he added. "We are into the last bit of the competition now. If you are not excited by this, you are in the wrong game.
"It's seize the moment time. These opportunities don't come around very often. The last time was 2011, and we just missed out then.
"You want to be involved in the big games, and there is no bigger than the World Cup final. So it's on, isn't it?
"We need to get back down to the 14-point line we were conceding in the Six Nations.
"We are only five above it in this tournament – we are averaging around 18 or 19 points in each game – which is pretty good. It's okay.
"If we get down to that 13-15 points, I think that will help us for our attack to try and cover that."
Wales have won five of their last six Tests against South Africa – four in Cardiff and one in Washington DC – but Edwards added: "I don't think it has any bearing on the game. Each game is a different entity.
"I used to get asked that a lot when we were going through that poor run against Australia.
"What we have done in the past will have no bearing on what will happen in the semi-final."