Doncaster Knights will take a 13-point lead into their Championship semi-final second-leg tie against Yorkshire Carnegie at Castle Park on Sunday.
Knights, who had been quoted as underdogs by the bookies going into the game despite pipping the Leeds club for the runners-up spot, upset the odds by posting a 30-17 win at Headingley.
Knights led 17-0 at the end of a dominant first-half showing and led 27-3 at one stage in the second half before the home club ran in two late tries to keep the tie alive.
“They finished well and I would have been disappointed had they scored another try late on, as they threatened to do, but I would have settled for a 13 point win at the start of the game,” said Knights’ boss Clive Griffiths.
“We’ve got a cushion going into the second leg but we know that they will throw everything at us on Sunday and they’ll be looking to start how they finished.
“It’s certainly not over by any means and the job is only half done, but we have some points in the bag and they are going to be very useful in what I expect will be a ding-dong affair at Castle Park.
“The first score is obviously going to be important. If we score the first try they’d have to score three to get back on terms but if they score first they are back in the game.”
Knights will go into the game without wing Andy Bulumakau, who limped off with a calf injury midway through the second half after scoring a first half try.