The 25-year-old was by far the fastest in the heats and then won a closer final in 2:08.01 to add his name to the growing list of Commonwealth Games qualifiers.
While the Glasgow 2014 ambassador impressed spectators with his classy effort, he was not particularly happy with his performance, admitting it had been tough. "I ran out of juice in the final 50m and it was pretty rubbish," he claimed after holding off Ross Murdoch by just over a second. "I had a really good swim in the morning heats but I think I got a bit too excited and I couldn't sleep in the afternoon and didn't have much left in the tank. I'm also a bit rusty. I haven't swum competitively since mid January. But the British Championships are back here next week and I'll definitely go faster."
Murdoch (2:09.15), who had set a British record in winning the 50m breaststroke on Thursday, was also inside the Games qualifying mark and so was third-placed Calum Tait (2:11.02).
Having missed out on the qualifying time in winning the 100m freestyle on the opening day, another of the local favourites, Robbie Renwick, was relieved to post a Games mark and win the 400m freestyle in 3:48.34. Second-placed Dan Wallace (3:49.464) and bronze medallist Stephen Milne (3:51.53), who had already won the 1500m freestyle, were also inside the mark for Glasgow 2014.
"I'm so much happier than last night," said City of Glasgow's Renwick, the two-time Olympian and 200m Commonwealth Games Champion. "I was far too tense before the 100m and I've got to address that before the Games.
"I am fine at Olympics and Commonwealth Games, but it is the qualifying meets that I find so hard. You can't be arrogant about making the times and you've got to be sharp from the first day."
Hannah Miley completed an individual medley double and added a second Games qualifying time in 2:12.94 in the 200m individual medley. The experienced Garioch swimmer won the 400m medley at the New Delhi Games in 2010 and the two-time Olympian will be one of the home favourites again in July.
In the final race of the day, Miley also won the 800m in a Games qualifying in 8:36.49 - fellow medallist Aisha Thornton (8:56.80) and Camilla Hattersely (8:36.91) also made it.
There were a hat-trick of Games qualifiers in the women's 100m breaststroke. Edinburgh University's Kathryn Johnstone got the touch in 1:0.71 ahead of training companion Corrie Scott (1:08.99). Katie Armitage also made it in 1:09.43.
Johnston said: "I wasn't sure of my form coming into these championships so I was delighted win. Corrie and I push each other in training and it is great that we have both got nomination times."
University of Stirling's Sian Harkin was another to make the standard, winning the 50m freestyle in 25.57. Warrender's Craig McNally, who swam for Britain at last year's World Championships, won the 100m backstroke in 55.42sec, just missing out on a Games time. He goes in his favourite 200m today. In the same final, 15-year-old Craig McLean (Carnegie) finished seventh, setting a Scottish junior record of 58.21sec.