Stingrays coach Graham Shaw believes last week's drought-breaking win will be wasted if Illawarra don't put in another good performance against Northbridge on Sunday.
The Rays ended their four-game winless run with a 3-1 victory against North West Sydney Koalas on Sunday to move off the bottom of the competition.
But Shaw is adamant his squad need to build on the momentum of that result.
"We spoke about that after the game [on Sunday]. We enjoyed picking up the points but we knew it would all be for nothing if we go to Northbridge and don't get any points next week," Shaw said.
"Northbridge are only three points above us, so getting that result up there will get us right back into a position on the table where we really want to see ourselves."
Illawarra currently sit eighth in the league, but are just four points behind third-placed Sydney University.
Northbridge sit just outside a finals spot.
They defeated the Stingrays 3-2 in a meeting earlier this year before Illawarra suffered heavy defeats to Sydney University and title-favourites Macarthur.
But the change in fortune last weekend has Shaw buoyed for a result reversal on Sunday.
"We need to keep doing what we have been doing," he said.
"Go in there with the right attitude, hold more possession than them and take our chances."