Olympic champion Kyle Chalmers upstaged by defending champ in dramatic final

Olympic champ Kyle Chalmers picked up a silver medal in the Men’s 100m final at the FINA World Championships despite swimming a personal best.

In an incredibly fast final, American Caeleb Dressel swam 46.96 seconds - just 0.05 seconds off the world record - pipping Chalmers who touched the wall at 47.08.

Dressel started strongly but in the last 30m Chalmers made his charge to draw level with the American.

However, Dressel found some energy to touch the wall just ahead of the Aussie.

Dressel’s time was also the fastest ever swim in a textile suit.

HUGE TWIST: Swimmers facing bans over Sun Yang podium protests

Russian Grinev Vladislav picked up the bronze medal.

Chalmers was looking shaky heading into the final and admitted he feared he may crash out in the 100m semi-finals after a disappointing 200m freestyle campaign in South Korea, failing to qualify for the final.

He was a lowly 10th fastest for the semi-final in 48.66.

But he finally sounded his intentions when he shaved more than a second off that to clock 47.58 to ensure Dressel will be looking over his shoulder in the final.

"Swimming is a huge mental challenge. I thought I prepared myself pretty well for this morning and didn't have the best swim," Chalmers said.

"You probably start to doubt yourself a little bit. I think I probably let that 200m affect me a little bit.

"I got stressed out a little bit. Tonight, I came out and gave it my all and that gives me confidence going into tomorrow."