SWINDON’S Jazz Carlin admitted her time to qualify her for the final of the 400m freestyle final surprised even her.

The 25-year-old overcame first-day nerves to record a personal best time and new Welsh record to secure the second quickest time of the heats earlier this afternoon.

The Tigersharks swimmer, who now lives in Bradford on Avon, won heat three as she recorded a time of 4 minutes 2.83 seconds, 0.41 seconds better than her previous personal best.

Carlin surprised many as she finished ahead silver-medal favourite Leah Smith (4:03.39) and Canada’s Brittany MacLean (4:03.42).

The Commonwealth gold medallist’s winning time was only eclipsed by favourite Katie Ledecky of the United States, who set a new Olympic record of 3:58.71 in the last of four heats.

“I’ve been feeling in great shape and had a really consistent block of training and racing,” said Carlin.

“I knew I was feeling good but I was so nervous for that first race.

“I know my coach will be happy for me to come away with a best time and I didn’t expect it to be that time.

“Obviously nobody wants to miss out on the final.

“We knew it would be tough to be in the mix for the final – there were seven girls on 4:03 going into the race.

“I knew I would have to post a solid time but I felt great. I didn’t feel like I was absolutely giving it everything. So hopefully tonight I’ll be in the mix.

“The Olympics is something special and I knew I would have to pull something out of the bag to put in a great swim and obviously it’s nice to do that for my first swim and it’s definitely given me some confidence and belief for tonight.”

FIND OUT HOW JAZZ GETS ON IN TONIGHT'S OLYMPIC FINAL (3AM) HERE