Buddy Budweiser was also impressive in a steeple win and Whata View shaped well as a hurdler.
The trials were over six fences, with five permanent fences involved for the steeplechases.
Sunkai, ridden by apprentice Daniel Stackhouse, went to the front at the third-last fence and won by four lengths.
The trial qualified him for steeplechases.
The Terry Kennedy-trained 8yr-old has won two flat races and been placed in four of his seven starts over hurdles.
He was runner-up to stablemate Art Protector over hurdles at Oamaru on May 14 at his last start.
Art Protector and First Prize also earned steeplechase tickets yesterday.
Gioarchino qualified as a hurdler.
Buddy Budweiser took the lead near the 900m in his heat and won by four lengths.
The Brian and Shane Anderton-trained gelding had qualified for steeplechasing when he schooled at Wingatui last week.
The Seasoned Star gelding won over hurdles at Riverton last month.
Whata View impressed rider Tom Hazlett when he made the pace yesterday and held on by half a length from Radical Ruler.
Whata View, trained by Graham Dobbs, has won twice on the flat.
Hazlett rode Vinopolis and Smeagol to win the other heats for hurdlers yesterday.
Vinopolis won a maiden hurdle at Riccarton and finished sixth in the Grand National Hurdles last winter.
Smeagol has been placed in her three starts over hurdles.
Results.-Weather, fine; track, dead (5).
Hurdles, 2200m (first heat): Smeagol T Hazlett 1; Blazing Away 2; Daatldomee 3. Four started. L, 1L. Time: 2.42. Trainer: P Gerard.
Second heat: Vinopolis T Hazlett 1; Ben's Dream 2; Beantheredonethat 3. Three started. 1L, 2L. Time: 2.44. Trainer, P Gerard.
Third heat: Whata View T Hazlett 1; Radical Ruler 2; Gioarchino 3. Three started. L, 1L. Time: 2.39. Trainer, G Dobbs.
Steeplechase, 2200m (first heat): : Buddy Budweiser S Moir 1; Art Protector 2; Firstprize 3. Four started. 6L, L. Time: 2.42. Trainers, B and S Anderton.
Second heat: Sunkai D Stackhouse 1; Son Of The Oak 2; Ice Pack 3. Four started. 4L, L. Time: 2.41. Trainer, T Kennedy.
The TAB is to increase fixed dividend betting on thoroughbred races, NZPA reports.
The TAB will offer fixed dividend betting on all rating 70 and above races from Wednesday.
This will increase the number of fixed dividend betting races by about six in the winter and 12 in the summer.
The TAB said fixed odds betting turnover was about $24,000 per race.
