Featherstone Rovers lost their third pre-season game on the spin as they were beaten by National Conference side Hunslet Club Parkside.
Stand-in coach Paul March named a makeshift side, with a total of 13 reserve players named in the home side's 20-man squad.
Featherstone included six reserve players in their starting line-up, three of which are on first-team trial.
They were without both new signings from Batley Bulldogs in Brad Day and James Harrison, with the latter ruled out by a knee injury picked up at Dewsbury Rams last weekend.
Rovers are still awaiting the arrival of their newly-appointed head coach, Ryan Carr, who is due in England on Tuesday.
Overseas-signings, Cameron King, Ase and Watson Boas and Thompson Teteh are still yet to feature this pre-season.
Plenty of Featherstone's reserves players fronted up well against the best amateur team in the country.
It was the National Conference side that started the brightest, making more metres while restricting activity in their own half.
Michael Waite almost opened the scoring but he was well stopped by Jordan Taylor as he looked to charge over.
The visitors continued to press and got the reward their efforts deserved with a quarter of an hour gone.
Influential half-back, Danny Rowse started the attack from centre field, with Parkside working the ball quickly to Waite who found a gap to score.
After being under pressure for most of the contest, Kiedan Hartley showed his class to draw Featherstone level.
Hartley, who joined Rovers from Leeds Rhinos in October, burst through the Parkside line and rounded the full-back to stride clear and dive over.
The home side could have taken the lead soon after when Taylor flew over in the corner, but the referee called play back for a forward pass.
Parkside regained the initiative at the start of the second half as they punished Featherstone for knocking on the restart.
Fields looked to charge over between the posts before he was halted but he got the offload away which gave Elliot Morgan the space to stroll over.
Just before the hour mark, Featherstone took the lead for the first time following some great work from Jimmy Beckett.
The loose forward burst through a gap and ran at McShane before offloading to Nathan Wright who gathered well to run in behind and dot down close to the posts.
The away side regained the lead however as Liam Thompson crashed over for Parkside's third try of the afternoon.
Rovers struggled to find their rhythm going forward, as Parkside held on for a surprise win.
Featherstone Rovers: Hartley, Taylor, Fagan, French, Wright, Richardson, Maden, Darley, Punchard, Hawkins, Hardcastle, Davies, Beckett. Subs: Cranswick, Cooke, Walters, Balkestone, Worrincy, Ottewell, Wright.
Hunslet Club Parkside: McShane, Bowles, Elliot, Waite, Squires, Hullock, Rowse, Healy, Murphy, Fields, Shulver, Thompson, Bradley. Subs: McShane, York Stanley, Biscomb, Foster, Hoyle, Morgan.