James Guy set a British 400m freestyle record as he and Siobhan-Marie O'Connor both claimed silver medals at the World Short Course Championships.
Guy, 19, beat Robbie Renwick's 2008 record in the heats before clocking an even quicker time of three minutes 36.35 seconds in the final in Doha.
O'Connor, also 19, then clinched silver in the 100m individual medley.
There was bad news for fellow Brit Fran Halsall who had to withdraw from the event because of a shoulder injury.
British Swimming described the injury as a "minor issue" and said the freestyle and butterfly specialist, from Southport, had pulled out as a "precaution".
The story of the night from a British perspective, though, was Guy.
The Millfield swimmer was denied gold by a superb display from Hungary's Peter Berner, who beat the championship record held by Australian great Grant Hackett since 1999 to claim gold.
But Guy was delighted with his own record-breaking display.
"It just felt great," he said. "I've honestly never felt that fast - I am over the moon with that, I am just so happy.
"I could see Peter was in first and I thought 'he's gone, I'll just do my own race'. My coach told me to try and build and build and build and that is what I did. It just felt great from there.
"It's my first major short course and I've medalled so I'm over the moon."
O'Connor had twice lowered her own British record en route to Friday evening's 100m IM final for which she qualified fastest.
While she could not replicate that in the final, the 19-year-old took a second silver of the meet behind Katinka Hosszu as the Hungarian won in a new world record time.
This added to her second place as part of yesterday's 4x50m mixed medley relay squad.
Halsall was also a part of that team, who set a British record time in winning silver on Thursday.
After her withdrawal from the event was announced on Friday, the 24-year-old tweeted: "Life would be boring if it was a straight line from A to B. Appreciate what you have, strive for what you want and expect it to be a challenge."
Elsewhere, Reading's Adam Barrett secured a 50m butterfly semi-final place as he equalled the British record of 22.87 seconds - which he now shares with Mark Foster and Antony James.
Chris Walker-Hebborn secured a place in the 50m backstroke semi-finals while Jazz Carlin, who has already won silver in the 800m freestyle, reached Friday evening's 400m freestyle final.
In the breaststroke, Adam Peaty failed to qualify at 200m and Sophie Taylor was eliminated in the 100m.