Stepping up to Grade One company for the first time, Paul Nicholls' charge was sent off the 5-4 favourite after impressing with wins at Chepstow in October and at this track last month.
Harry Cobden was happy to sit in third for much of the extended two-and-a-half-mile trip as High Stakes set out to make all with Lossiemouth racing on his heels.
All seven runners looked to have a chance turning for home, but as Lossiemouth started to toil, it was evident Stage Star was travelling much the best and he grabbed the initiative at the penultimate flight.
Cobden then kicked on and Stage Star cleared the last in style to come home six and a half lengths clear of the staying-on West Balboa.
Stage Star was cut from 16-1 to 8-1 for the Ballymore Novices' Hurdle at the Cheltenham Festival in March.