Danielle Hill's list of national titles at this year's five-day Irish Open meet now stands at five after the Olympian won her favoured event, the women's 100m backstroke, in 1 minute 0.87 seconds.
It was close to her own Irish record as she continued her build-up for both the European Championships and Commonwealth Games later this year.
Hill had already won the women's 100-metre freestyle national title in a new Irish senior record time earlier in the week and the 23-year-old also touched home first in the 50 butterfly, 50 freestyle and 200 backstroke.
The 23-year-old from Larne could well make it six straight wins in her final event of the meet, the 50m backstroke, on Saturday.
The top men's race of the night was the 200m breaststroke, where NCL’s Eoin Corby eased past Uiseen Cooke in the last 25 metres to win the title in 2:12.82 and complete the clean sweep of 50, 100 and 200 breastroke wins
Tokyo Olympian Jack McMillan produced a fine swim to take the men’s 200m freestyle gold medal from lane one, the Irish record holder in the event out-foxing the faster qualifiers in the middle lanes to win in 1.47.93, a good early-season time and just over a second outside his Irish best time.
Fellow Olympian Finn McKeever took silver, ahead of Robbie Powell in bronze.
Conor Ferguson won a terrific men’s 100m backstroke final in a very respectable 55.40 seconds, denying Ards swimmer Paddy Johnston, who was looking for his third win of the week, with his team-mate Adam Barnes in bronze.
Earlier, 17-year-old Molly Mayne from Templeogue won the opening event of the evening, the women’s 200m individual medley, winning easily in a time of 2:16.59.
It was Mayne's second national title of the week, having won the women's 100m breaststroke on Tuesday.
Alana Burns-Atkin (Bangor) won the women's 200 butterfly gold, the 16-year-old claiming victory in 2:20.90 while Grace Hodgins won the final race of the night, the women’s 800m freestyle, in 8:56.44.
That was Hodgins' third win of the week after already tasting victory in the 400 and 1500 freestyle.