They went into the game knowing that they could not afford to lose as the bottom two teams clashed.
With a couple of long-term injuries and some unavailabilities, coach Gavin Barton had to shuffle his playing squad and deployed back row forwards Andy Tissingh and Ben Kelsall in the back line as centres.
Garstang dominated from the off but were constantly thwarted by a resilient Oswestry defensive effort.
The dam finally burst after 15 minutes and Garstang took the lead as the ball was spread out wide to Freddie Hewitt who went over in the corner.
A few minutes later and another period of sustained pressure saw Tissingh crash over from close range to make it 10-0.
The second half started in similar fashion as Garstang’s dominant forward pack set up a superb platform.
However, the fickle confidence and lack of belief led to an unbelievable amount of squandered chances.
This came to a head midway through the half when the team worked their socks off to create a three-on-one overlap but the ball was spilled with the line begging.
Straight afterwards, Garstang regained possession and looked to have scored but the ball was lost as the player stretched out to dot it down.
The pressure eventually told though as Garstang created a massive overlap and the ball was spread out wide to Hewitt, who scored his second try in the corner.
Minutes later the dominant pack sealed the win as a scrum was driven over from five metres and Greg Billington touched down to score the fourth try which secured the crucial bonus point.
All of the Garstang tries were scored in the corners, meaning Craig Johnston did not have any luck with the conversions as they led 20-0.
Despite the game being over as a contest, Oswestry team refused to lie down.
They had their one and only period of dominance in the last five or 10 minutes and were rewarded with a try in on the stroke of full-time.
Garstang’s seconds also had a successful day as they beat Orrell St James by 39-7.
Both are back in action on Saturday as the first XV travels to play Birchfield and the Blues are at Wigan’s seconds (both 2.15pm).