Adam Peaty breaks world record, James Guy claims shock gold

Peaty's time of 26.42 seconds broke the previous record of 26.62 seconds set by South Africa's Cameron van der Burgh in the morning heats earlier on Tuesday.

"I feel pretty stoked really," said Peaty. "The heats this morning were so easy and I just chilled out this afternoon – I wasn't too tense.

"I went out there, improved my start and just let the swimming swim and that's what I do all year round.

"It's going to be a good final. Cameron's a great guy and it's going to be a great race tomorrow."

Earlier, James Guy took gold in the 200m freestyle with Olympic silver medallist Sun Yang of China second by six hundredths of a second.

"I never thought about beating Sun Yang or anyone," Guy told British Swimming. "I just thought about swimming my own race and getting my tactics right and if I beat anyone it was a bonus.

"I never thought I'd even make the final. The main focus for me was the 400m free and I was so happy with silver but I did want to go a little faster in that final.

"Obviously I never thought I'd win the 200m as well so it’s a nice feeling.

"There's more there for me though. You look at Ryan Lochte's underwater phases and he's like a dolphin. So if I had them, I could go even faster."