Jamieson powered to maximum points in the 200m breaststroke clocking 2:01.83 to edge out team-mate, Germany's Marco Koch, by seven hundredths of a second.
“There was only 0.3 between myself and Marco last week and I think tactically I went for the win rather than the time,” said Jamieson, who set a 2:01.43 British record at last week's European Short Course Championships.
“I was probably out a bit too slow and bit too controlled there because I was watching what was going on in the race.
"I did leave it too late but it was alright and I got the result I wanted in the end.”
Elsewhere, British swimmers Aimee Wilmott took second in the 400m medley while Adam Brown finished just behind European team-mate Yannick Agnel in the men's 100m freestyle.
And world bronze medallist Fran Halsall helped the European women's 400m medley team to victory.
Europe, seeking to win their first ever Duel in the Pool title, lead the USA by 68-54 heading into Saturday's concluding day.