Riverina got off to a perfect start in the Country Championships.
Both the women's and under 23 sides scored wins on the road against Newcastle.
Riverina started strong before getting into a real arm wrestle at St Mary's Leagues Stadium in Penrith on Saturday.
There was little between the two teams during the middle stages of the game before late tries to Young pair Casey Wall and Jesse Corcroan sealed a 26-18 victory.
Coach Jody Rudd was thrilled with the side's defence.
"Defensively I thought we had a really good game," Rudd said.
"We fixed up a lot of the issues we had in our trial match, particularly on the edges, and I thought we controlled the ruck defensively very well.
"For them to get into good field position it really relied on our errors, some intercepts and some dropped balls.
"From that point of view the defence really showed the attitude the guys came into with.
"They've got a really positive attitude, didn't panic when we got behind in the game and I think they knew we could grind our way to a win."
However there is plenty to work on.
Especially after giving Newcastle plenty of opportunities to get back into the game.
"It was probably a little more greasy than what it looked," Rudd said.
"It was pretty humid and we had a little bit of rain which made ball control a little bit tough.
"Newcastle were pretty scrappy around the ruck as well, there were hands around the ball, which we didn't handle as well as we should have."
The forward pack had to get through plenty of work with Liam Headon dislocating his shoulder.
Front rowers Zac Masters and Luke Ingram both impressed in the middle with Hayden Philp also strong in the pack.
Headon isn't expected to be fit to play in round two while the Bulls are also monitoring a thigh injury to fullback James Girdler.
Meanwhile the women were much more comprehensive in the time first time a tackle competition has been introduced.
Emma Hickey scored twice as the girls scored a 22-6 victory.
It places both sides in a good position to make finals despite coming up against Illawarra in the second round.
The top teams from across the state will make the semi-finals to be played on March 30.