Saints started brightly and they opened the scoring early on, Paul Crook saw a gap in the Oldham defence before powering his way over the line.
Both teams coped well in defence and cancelled each other out for much of the first half hour. However pressure paid off for the hosts, following a number of penalties near the try line and they found their first try.
Roughyeds moved the ball to the right hand side and following a looping pass, Declan Kay crossed narrow the scores.
Minutes later Oldham scored again. A short inside ball saw James Worthington find a gap, before touching down to give the home side the advantage going into the break.
Again, Saints started the second-half the stronger side and their first real attack saw Matt Costello score in the corner, following some quick play to get the ball out wide.
The second period was pretty similar to the first with both teams doing most of their work through the middle.
Oldham then had a chance to regain the lead, after the ball was shifted out wide and Kay looked to have found his second, only for stand-in full-back Tom Nisbet to make a fantastic try saving tackle.
However it wasn’t long until the Roughyeds did cross the line, minutes after Saints thought they had gone over to score through Josh Simm. An Oldham attack saw Danny Bridge cut inside to touch down.
Saints fielded some of their younger stars in the final 20 minutes and the difference in size and experience began to pay off.
Bridge went to cross again minutes after his first, after some nice handling from the hosts saw a gap open in the Saints defence and the second rower made no mistake.
Oldham’s dominance was a sign of things to come and some more clever play saw the ball find its way to full-back Kyran Leeming who went in under the sticks to put the result beyond all doubt.
Just before the full-time hooter sounded a high-hanging kick found its way into the arms of Harry Arronson, who climbed above the Saints defenders, to score with the last play of the game.
Saints Team: Owain Abel, Nico Rizzelli, Matty Costello, Josh Simm, Tom Nisbet, Paul Crook, Lewis Dodd, Callum Hazzard, Josh Eaves, Alex Eckley, Joe Batchelor, Mike Weldon, Sam Royle.
Interchanges: Paul Nash, Kye Siyani, Ben Davies, Jamie Pye, Harvey McDaid, Jumah Sambou, Lewis Baxter, Harry Brooks, Keenan McDaid.
Tries: Paul Crook, Matty Costello.
Goals: Lewis Dodd (2)
Oldham Team: Dan Abraham, Declan Kay, James Worthington, Ed Smith, Kyran Johnson, Lewis Charnock, Dave Hewitt, Phil Joy, Gareth Owen, Jack Spencer, Danny Bridge, Danny Langtree, Liam Bent.
Interchanges: Harry Aaronson, Adam Brook, Matty Wilkinson, Danny Igbinedion, Matthew Fletcher.
Tries: Declan Kay, James Worthington, Danny Bridge (2), Kyran Johnson, Harry Aaronson.
Goals: Dave Hewitt (4).