Doncaster Knights will battle it out with derby rivals Yorkshire Carnegie for a place in the Championship Promotion Play-off final.
Just 24 hours after Knights secured second spot, the Leeds-based club clinched third with a 37-27 victory over Nottingham at Headingley.
The two clubs are expected to finalise details of the two-legged semi-final in the next day or so with Knights having choice of being home or away in the first leg.
Knights made sure of retaining second spot, which represents their highest finish, with a 28-24 win over Bedford and director of rugby Clive Griffiths said: “It wasn’t one of our best performances but it was all about getting the win and we did that.
“It’s a landmark occasion for the club to finish in second place and everyone connected with the Knights should be proud of what we have achieved in only our second season being back in the Championship. “
Griffiths said he had expected a tough challenge from Bedford, who were looking to hold on to their top-four spot, but admitted he hadn’t expected his charges to concede a first minute try after full-back Paul Jarvis had been stripped of the ball from the kick-off.
“We were 14-3 down at one stage in the first half and it has to go down as one of our worst first-halves of the season and I needed to say a few things to the players at half-time,” he said.
“We played better in the second half but it remained close and you are always worried in that situation that they could pip you at the death, as did Bristol in our last home game, but we defended well.”