Williams celebrates his bronze medal in Sweden with sister Kathy

The 22-year-old from Cardiff, son of Wales rugby legend JJ Williams, produced a storming finish to snatch third by one hundredth of a second.

He said: "My parents were here watching and I'm glad they can go home with something to be happy about.

"I'm so lucky to have them. They've spent so much time and money supporting me, it's nice to give something back."

Highlights: Day four in Gothenburg

That medal looked a distant hope as Williams hit the home straight second last on Thursday night.

But he surged through the field in the closing stages to pip 2004 Olympic bronze medallist Naman Keita on the line in a time of 49.12 seconds.

We opened some champagne and there was a lot of Cardiff Athletic Club people there to celebrate with Rhys JJ Williams

Williams, though, admitted he had got his tactics wrong and feared he had again finished in the position all athletes dread.

"I thought I was fourth," he told BBC Sport. "I had fourth in the 2004 Commonwealth Games I was thinking 'oh no not again'.

"It wasn't a good race. I went off a bit too slow but I was so nervous. I'm so happy I managed to come through.

"With 100m to go I think I was about last position. I told myself to stay relaxed because I knew I could come through. But I was lucky, it was too close to call.

"I was desperate to get a medal. The Olympics and Worlds are such a high standard, I knew this could be my only chance to get a major medal.

"I've done it at youth and Under-23 level so I'm glad to come away with something. Hopefully I can build on this."

Williams' parents and sister were in the stadium in Gothenburg and father JJ revelled in his son's achievements.

"I'm very proud," said JJ, who represented Wales in the 4x100m relay at the 1970 Commonwealth Games.

"We had a great night. We opened some champagne and there was a lot of Cardiff Athletic Club people there to celebrate with Rhys.

"Briton had been struggling for medals but then Rhys won his bronze and then two more came quickly after that.

"He set them on a bit of a roll. All of a sudden the atmosphere has changed thanks to Rhys."