Dewsbury’s hopes of playing in the inaugural Championship Shield Grand Final were ended by defeat to London Broncos.
The sides went into half-time locked at 16-16 and when Shane Grady hammered over a 51st-minute penalty, there was hope the Rams were set for victory.
However, Rhys Williams picked up a dropped ball and raced over for a crucial try, which William Barthau converted.
Daniel Harrison then scampered to the line following a scrum and Barthau converted.
Dalton Grant had a try ruled out for a forward pass as Dewsbury looked to hit back and London rubbed salt into the wounds when Harrison pounced for a last minute try, which Barthau improved.
Dewsbury had taken a first-half lead in some style when winger Dale Morton intercepted a pass on his own line and raced the length of the field. He was tackled inches short but flipped the ball inside for Anthony Thackeray to touch down. Tom Hemingway converted.
Ben Hellewell replied with a try for London, which Barthau improved. Dewsbury then appeared to have taken control as Morton dived over for a spectacular try and Etu Uaisele was on the end of a fine passing move to score soon after, with Grady converting the latter.
Dewsbury’s 10-point lead was whittled away as Joe Keyes and Iliess Macani scored to bring London level and the Broncos took control in the second half.
Dewsbury Rams: Fieldhouse; Morton, Pryce, Uaisele, Grant; Wildie, Thackeray; Hepworth, Hemingway, Aizue, Grady, L Adamson, Farrell. Substitutes: Conroy, Crookes, Jackson, Nash.
London Broncos: A Walker; Williams, Hellewell, Kear, Macani; Barthau, Keyes; Riley, Cunningham, Diollapi, Harrison, Garside, Davis. Substitutes: Henderson, Thackray, Everett, J Walker.
Referee: J Roberts (RFL).