Olympic and world champion Adam Peaty earned a dominant 100m breaststroke victory on day two at the McCullagh International meet in Northern Ireland.
Peaty clocked 58.78 which was 1.90 seconds outside his world record mark.
The Englishman's Loughborough club-mate and world silver medallist James Wilby took second in 59.91 with Scotland's Ross Murdoch third in 1:00.54.
Peaty, 25, is also competing in the 50m and 200m breaststroke events at the Bangor meet.
The event is following the same format as this year's Olympics with heats taking place in the evening followed by morning finals.
Peaty admitted that the format change will take some getting used to but he was happy with his Friday morning swim.
"It was very good. It's always harder coming in racing in the morning especially when you are not used to it," Peaty told BBC Sport Northern Ireland.
"This is the start of my prep now. It's only a few months to the Olympics and we're just looking at how we can get those extra gains."
Hill dead heats in women's 50m backstroke
Ireland's Danielle Hill and Scotland's Kathleen Dawson dead-heated in the women's 50m backstroke final.
The duo shared the top podium spot with a time of 28.35 seconds.
There was also a dead heat in the women's 100m breaststroke as English duo Siobhan Marie O'Connor and Sarah Vasey both touched the wall in 1:08.15 - 0.05 seconds ahead of Ireland's third-placed Mona McSharry.
Britain's Olympic silver medallist Duncan Scott clinched a comprehensive 100m freestyle victory as his time of 48.86 seconds left him 1.06 ahead of Ireland's Shane Ryan, with Northern Irishman Jack McMillan going under 50 seconds for the first time as he clocked 49.97 to take third.
Englishmen Max Litchfield and Edward Mildred filled the top two spots in the 200m butterfly with times of 1:59.53 and 1:59.97, with Ireland's Brendan Hyland third in 2:00.04.
There was a British one-two-three in the women's 400m individual medley as England's Commonwealth champion Aimee Wilmott [4:39.63] came in ahead of Scottish pair Hannah Miley [4:44.60] and Kate Shanahan [4:47.95].
Welsh star Alys Thomas won the women's 200m butterfly in 2:10.07 to finish 1.40 seconds clear of Loughborough's Charlotte Atkinson while Ireland's McSharry earned a home success as she clinched the women's 100m freestyle in 57.05 seconds.