Featherstone Rovers came from behind and held off a late comeback to post a 32-24 victory over Widnes Vikings at Stobart Stadium.
The win means that Rovers face Halifax to decide who will meet Barrow Raiders in the Co-operative Championship Grand Final.
Widnes are eliminated from the play-offs, but are already eligible to apply for Super League in 2011 due to their Northern Rail Cup win.
The Vikings started the brighter, James Webster held up over the line before Anthony Thackeray sent Gavin Dodd over to score, Tim Hartley converting.
That lead was extended with a last-tackle play, Dean Gaskell with the break and the pass for Lee Doran to extend the lead, Hartley again adding the two points.
Rovers, however, hit back when Andy Kain dummied his way over the line, Iestyn Harris converting, followed by touch down from Kyle Briggs.
Harris’ second conversion levelled the scores and a penalty goal just before the half-time interval edged the visitors into the lead for the first time.
Fev started brightly – a try was disallowed for a forward pass – and the lead was extended when Waine Pryce took an interception from Gavin Dodd and went 85m to score.
Harris converted from the touchline, and kicked yet another game after Jack Lee was able to spin out of a tackle to give the visitors a 26-12 lead.
Widnes hit back with a try from Shane Grady, Hartley converting, and a comeback was on the cards when Richard Varkulis powered his way over, Hartley’s goal cutting the gap to two points.
But Featherstone sealed the win and their passage to the next round of play-offs when Harris burrowed his way over on full time, adding the extras to his own try.