Chris Waller and Gai Waterhouse finished one-two in last season's Sydney trainers' premiership but there was nothing between them after the first meeting of the new term.
The pair produced two winners apiece at Hawkesbury on Wednesday with Waterhouse striking first, taking the opening two races on the card.
Filly Queenstown lived up to her good barrier trial form in the first race but it was the flashy performance of three-year-old Proisir that took centre stage after he overcame a tardy start to score a dominant victory.
"He won that in the style of a really good horse," Waterhouse's racing manager Mark Newnham said.
"There's a little bit of work to do there (in the barriers) but he's certainly got the motor."
Proisir also drew praise from winning jockey Nash Rawiller who was taken aback by his finishing sprint.
"This is a very promising horse," Rawiller said.
"Geez he was exciting the last 200."
Waller got on the board when recent acquisition High On Believing scored an against-the-odds win in the TAB Sportsbet Handicap (1200m).
The former Queenslander was well back entering the straight and had to bide his time for a split to present itself but once clear he unleashed a devastating sprint to mow down the leaders and score.
Waller said High On Believing, raced in the same interests as stablemate and Chipping Norton Stakes winner Shoot Out, was now likely to step up to Saturday grade.
Leading Sydney trainer for the past two seasons, Waller notched his double when European import Thubiaan just lasted to take out the final race.