Great Britain continued to impress in the pool with a number of impressive performances promising more medals tonight, with a clean sweep in the men's S8 400 metres freestyle a distinct possibility.

The Hynd brothers, Sam and Oliver, and Thomas Young filled the first three slots in qualification for the eight-length race to raise the spectre of a repeat of their one-two-three at last year's European Championships in Berlin.

Heather Frederiksen appears well placed to claim a medal in the women's equivalent, four years after winning silver on her Paralympic debut in Beijing.

Chloe Davies headed the field in the S14 100m backstroke with team-mates Jessica-Jane Applegate and Natalie Massey third and seventh respectively.

Susie Rodgers (S7 50m butterfly), James Crisp and Morgyn Peters (S9 100m backstroke), Stephanie Millward and Amy Marren (S9 100m backstroke), Aaron Moores and Ben Procter (S14 100m backstroke) and Matt Walker (S7 50m butterfly) all go in tonight's finals.

Laurence McGivern (S9 100m backstroke) and Bethany Firth (S14 100m backstroke) will carry Irish hopes in their respective finals.

Jonathan Fox won Britain's first gold in the pool last night in front of a raucous crowd at the Aquatics Centre and it is possible there will be another home-grown winner tonight.

Sam Hynd led the way in four minutes 33.25 seconds with younger brother Oliver third and Young sandwiching the two.

For the elder Hynd - the defending champion and world record holder - felt his race had gone to plan and he said: "A very good swim, I was really pleased with how it went.

"The tactics were right on what me and my coach set.

"I'm glad to get the heat out of the way. All the pressure's off after that."

Brother Oliver was less pleased however with his time of 4mins 36.40secs, saying: "I would have liked to have been a little bit faster but I've got another opportunity to swim faster tonight."

Of whether he would spend time with his brother before the final, he said: "We don't really talk about it: we just go about our normal business and then meet each other in the pool."

Young, though, was more satisfied with his 4:34.16 effort and believes they can repeat their clean sweep from Berlin.

He said: "I just wanted to go in and see what I've got and it shows I've got a lot left in the tank for that final tonight so it could be a one-two-three I reckon."

Asked about the crowd reaction to Fox last night, Young said: "[It] put hairs back on my chest even though I'd shaved down."

Frederiksen was hospitalised following a diagnosis of neuralgic migraines but she overcame her ill-health of the last year to qualify second for the women's equivalent.

While her time of 4:58.29 was more than 15 seconds ahead of Australian Maddison Elliott in third, the Briton was almost 14 seconds down on Jessica Long who set a Paralympic record of 4:44.52.

Frederiksen won four medals on her Paralympic debut in 2008, including silver in this event.

She said: "To make these Games has been an absolute dream but to swim like I swam this morning and make the final and give it a good shot is fantastic."