JAZZ Carlin has booked her place in the final of the 800m freestyle with a third fastest time.

Having already claimed a silver medal in the 400m in the early hours of Monday morning, Carlin was back in action at the Aquatic Stadium in Rio this evening.

The 25-year-old, from Swindon, who lives in Bradford on Avon, went in the fourth and final heat of the 800m freestyle, alongside world record holder Katie Ledecky.

The Tigersharks swimmer started well and was turning in third after the opening 50m, 0.04 seconds behind the American.

Carlin moved herself up to second by the 100m mark and with a quarter of the race gone, she was still on the coattails of Ledecky, just 0.84 seconds behind.

However, when the American, who had beaten Carlin to gold in the 400m freestyle, stepped into second gear, the Swindon swimmer was unable to respond.

Carlin’s battle changed focus to Hungarian Boglarka Kapas, who beat the Commonwealth gold medallist to gold in the European Championships in London earlier this summer, as the 23-year-old closed the gap in third.

By the halfway stage, Carlin had fallen two seconds off the pace, with Kapas just 0.9 seconds behind.

The Hungarian took the lead going into the final 200m, taking a lead of 0.32 seconds at the turn.

However, Carlin did not let her get away and came home in third with a time of 8 minutes 19.67 seconds, 0.24 seconds behind Kapas, with Ledecky taking Rebecca Adlington’s Olympic record with a winning time of 8:12.86.

"She looked very comfortable and I think she is capable of getting that Commonwealth record and British record tomorrow night," said Adlington.

"For Jazz, she just needs to work on her turns a little bit as the other girls have got very strong turns and I do worry that Kapas and Leah Smith are over the other side of the pool tomorrow night.

"I think Katie Ledecky will be so far ahead that she will be able to see them."

Carlin will go in the final of the 800m at 2.20am (BST) on Saturday morning.