It took the 18-year-old’s tally for the competition to nine golds and two silvers.
Great Britain junior international Atkinson, competing for the Isle of Man, was just a class apart at the Games.
She won the 200m butterfly event on Thursday evening by nearly nine seconds. Atkinson clocked 2:09.37 with Cayman Islands’ former Plymouth College pupil Lara Butler second in 2:18.01.
Atkinson then won the 100m freestyle race in a time of 57.03 seconds.
To cap a good night in the pool, she then helped the Isle of Man to the women’s 4x100m medley relay gold and the 8x50m mixed freestyle gold.
Atkinson had previously won the 50m and 100m butterfly, 200 IM and 50m freestyle events and also claimed another gold in the 4x50m women’s freestyle relay and silvers in the 4x50m women’s medley relay and 4x100m freestyle relay.