Miley was hotly tipped to appear on the podium over 400m at London 2012 this summer however the Scot was blown out of the water by controversial Chinese ace Shiwen.
Aged just 16, Shiwen took both the 200 and 400m IM gold medals on offer amidst allegations of doping, fuelled by the Chinese swimmer clocking freestyle splits quicker than men's medley champion Ryan Lochte on her way to 400m gold.
Miley could only finish fifth in the 400m medley in London. However, she topped the timesheets heading into Wednesday's final with a time of 4.28.91.
Shiwen was just over a second back in qualifying third.
Miley said: "In the Olympics everyone was taken out of their comfort zone because they had to swim really hard to reach that final.
"Here we kind of have the luxury where we can play about a little bit, so tonight will be the big showdown.
"I think for her she [Ye Shiwen] backed off, as she just wanted to get into the lead and then hold a position in the top two."
Meanwhile London 2012 silver medallist Michael Jamieson celebrated his first competitive action since this summer's heroics by qualifying for the 100m breaststroke semi-finals.
Jamieson won his silver medal in the 200m breaststroke in the capital this summer but was in solid form over the shorter distance in Turkey.
The GB ace qualified 12th-quickest for this evening's semi-finals with a swim of 58.61 seconds, 0.95 seconds adrift of the fastest qualifier, America's Kevin Cordes.
Jamieson's smiles at securing his semi-final berth were shared by GB's lone ranger in the 200m butterfly Jemma Lowe.
Ordinarily Lowe would be swimming alongside Ellen Gandy however with Gandy's decision to swim for Australia last week the GB ace was flying solo.
Lowe won World Short Course Championships silver at the corresponding event two years ago and looked comfortable in qualifying for the semi-final in seventh overall - clocking 2.06.14.
Elsewhere Lizzie Simmonds, fourth over 200m at the Olympics, booked her spot in the 100m backstroke semi-finals along with Georgia Davies.
Jazz Carlin returned to competitive GB action for the first time since missing out on London 2012 through illness, helping the 4x200m freestyle relay squad qualify for the final.
There were some casualties for the GB squad, however: Craig Benson was unable to follow fellow Scot Jamieson into the 100m breaststroke semis. With the top 16 progressing, the 18-year-old ended 18th, just 0.08 seconds shy of qualification.
Chris Walker-Hebborn's time of 52.11 seconds was not enough to qualify in the 100m backstroke while Ieuan Lloyd and Robbie Renwick both missed out on the 200m freestyle final despite Lloyd clocking a new Welsh record of 1.45.67 minutes.
Lloyd was in fine form in the 4x100m freestyle relay with another personal best swim - but the GB squad missed out on the final.