Glasgow: England, South Africa and Australia all claimed two gold medals in the pool at the Commonwealth Games as world champions Cate Campbell, Cameron van der Burgh and Chad le Clos were victorious.
Jazz Carlin also won Wales first female swimming Commonwealth gold medal for 40 years in the 800m freestyle, whilst Audrey Lacroix claimed gold for Canada in the women`s 200m butterfly on Monday.
Australia have now won 17 of the 36 gold medals on offer in the pool in Glasgow and swept the board in the women`s 100m freestyle as Campbell just edged out sister Bronte by 0.18sec with Emma McKeon taking bronze.
South Africa`s star duo Van der Burgh and Le Clos had experienced very different meets before Monday, but were both back on top of the podium in contrasting fashion.
Van der Burgh hailed the most "emotional" victory of his career after bouncing back form disappointment in the 100m breaststroke to beat 19-year-old Englishman Adam Peaty to gold by just 0:02sec.
"It was one of the hardest races I have ever had in my life, said a relieved Van der Burgh.
Le Clos, meanwhile, doubled his gold medal tally for the meet and took his overall haul for the games to five medals with a comfortable victory in the 100m butterfly.
Joseph Schooling claimed Singapore`s first medal of the meet with silver ahead of England`s Adam Barrett in third.
Carlin posted a new personal best and smashed the Commonwealth Games record in a time 8min 18:11sec to take the women`s 800m freestyle.
The 23-year-old shaved over four seconds off the previous record she set in qualifying fastest for the final on Sunday.
World 800m freestyle bronze medallist Lauren Boyle took silver for New Zealand, whilst Brittany MacLean claimed bronze for Canada.
"It`s amazing. It has not sunk in it. Hearing the Welsh national anthem was amazing. I was trying to sing it but I just got too emotional," said Carlin.
And a fine evening for Wales was rounded off by Georgia Davies breaking the Games record in qualifying fastest for the women`s 50m backstroke in a time of 27:61sec.
Sophie Taylor set a new British record time of 1min 06:35sec in sealing gold for England as Australia`s Lorna Tonks took silver and Jamaica`s Alia Atkinson bronze in the women`s 100m breaststroke.
England`s Oliver Hynd was the most comfortable winner of the evening as he streaked clear of the field by nine seconds to win the para-sport 200m individual medley SM8 ahead of Aussie duo Jesse Aungles and Blake Cochrane.
Ben Proud continued England`s storming night as he also broke a British and Commonwealth Games record in qualifying fastest for the men`s 50m freestyle final in a time of 21:76sec.
Proud, though, will face stiff competition from Aussie trio Cameron McEvoy, James Magnussen and Matt Abood, as well as world championships bronze medallist George Richard Bovell of Trinidad and Tobago.
There was a another all-Australian podium of the meet in the men`s 200m backstroke as Mitch Larkin claimed gold ahead of Josh Beaver and Matson Lawson.
Victory secured Larkin`s third medal of the meet, but it was his first gold having taken silver in both the 50 and 100m backstroke.
"It has been a long week, but a fantastic week," said Larkin. "It feels unreal to get a gold tonight."
And Lacroix won Canada`s third gold of the meet and her fifth career Commonwealth Games medal to take the 200m butterfly in a time of 2min 07:61sec.
England`s Aimee Willmott picked up her second silver medal of the meet in second, whilst Australia`s Maddie Groves won bronze.