"Breaking the record was a bonus but she was very confident and very smooth and I think there is more to come."
A key for the final is Boyle's recovery, which went well after her exertions earlier in the week.
"She recovered very well from the 1500 which was obviously twice the distance," Lyles said. "The recovery should be faster. She has trained extremely well and hard and very long for this so the recovery is not an issue.
"It has been a long week and she has done something like 4000m of racing which is an awful lot in eight days. So it is the mental recovery which is important but she is very confident, she is very proud of what she has achieved so far and she is really gunning for another successful race."
Elsewhere, 18-year-old Christchurch swimmer Sophia Batchelor matched her best time to finish fifth in her semifinal of the 50m butterfly and 11th fastest overall. She was just 0.2s outside qualification for tomorrow's final.
Wellington's Gareth Kean is the sole New Zealander in the pool tomorrow morning in heats of the 50m backstroke on the penultimate day of competition.
