The Robins fought for a goalless draw at Brentford on Saturday, and then beat Conference side Stevenage in the LDV Vans Trophy on Tuesday.
They are still rooted to the foot of the table, but Onuora - who is in charge of the side after Andy King was sacked - reckons he now has a platform from which the club can push for safety.
He said: "It was a relief, but deserved for the effort we put in. The lads did very well.
"Saturday's draw at Brentford gave us the platform, and we won't let this result be a flash in the pan. It will give us back belief, and on the back of two decent results we can go anywhere now.
"But we are still adrift in the League and need to be positive and build our confidence.
"We certainly won't be underestimating Scunthorpe. They've had some good results and we have to respect them.
"However, we should have nothing to fear from this division, and we'll go into the game with confidence."