City of Sheffield's Nick Grainger continued to boost his international credentials with 400m Freestyle gold on day one of the Mare Nostrum leg in Barcelona.
The 19-year old, who will make his World Championship debut in Kazan later this year, clocked 3:48.29 to take the touch from Canada's Commonwealth champion Ryan Cochrane (4:48.69) and British champion James Guy (3:48.83).
Grainger's PB stands at 3:45.89 from his silver behind Guy at this year's British Championships in London.
But the teenager's effort in Barcelona ranked as his third fastest competitive time and was nearly four seconds quicker than his 3:52.15 swim from the final of the previous Mare Nostrum leg in Canet last weekend.
Adam Peaty, Jazz Carlin, Ben Proud and Chris Walker-Hebborn were the other Brits to top the podium on the first day in Barcelona.
European and Commonwealth champion Peaty - who set the 100m Breaststroke world record at the British Championships in London earlier this season - improved on his gold-medal winning time from Canet to take the top prize in 59.55.
Meanwhile, Carlin clocked a relatively modest 8:28.59 for victory in the 800m Freestyle with Keri-anne Payne just 0.18 seconds shy of her personal best from 2011 as she took silver in 8:30.16.
Proud and Walker-Hebborn won gold in the 50m Butterfly and 50m Backstroke events respectively, Proud stepping up from his bronze in Canet to take top spot on 23.70, and Walker-Hebborn moving one step up the podium from Canet for gold in 25.23 ahead of world record holder Liam Tancock (25.48).
Find out more about Nick Grainger in Looking Glass.