Sound Proposition lost a group one placing, his third in last year's New Zealand Derby behind Mongolian Khan and Volkstok'n'barrell, when disqualified for having elevated levels of cobalt in his system.
O'Sullivan and Scott were subsequently charged with presenting three horses to race with a prohibited substance, however the Racing Integrity Unit found they did not purposely administer cobalt in what was a highly publicised and protracted case.
"It's a very satisfying win," said O'Sullivan. "It has been a tough 12 months but we've all come through it and out the other side and as far as Wexford Stables goes it's onwards and upwards."
Sound Proposition has started just five times since his Derby performance and he showed he was back on the right track when winning a Rating 85 1600 at Ellerslie earlier this month.
"He came into the race through the back way - he wasn't in any of the big races coming in," said O'Sullivan. "He had to earn his spot in the race."
Settled back by Coleman, Sound Proposition unleashed his winning run wide out and nabbed outsider Trojan Warrior in the last stride to score by a head.
It was the fifth win in the Easter for Wexford Stables following on from Shivaree (1981), Our Shah (1982), Eastern Joy (1985) and Calveen (2005).
Trojan Warrior produced a huge effort for second as he was unsuited by the set weights and penalties conditions of the Easter.
Rasa Lila charged home late for third, a short neck from the runner-up, while Sakhee's Soldier was right in line in fourth position, just under a length clear of Mabeel.
- NZ Racing Desk.