Doncaster and Bristol both gained a big advantage in the Championship play-offs by winning their semi-final first leg.
The Knights survived a late Yorkshire Carnegie comeback to win 30-17 in their away leg at Headingley.
Bristol were even bigger victors as they ran in six tries in a 45-16 win against Bedford at Goldington Road.
The second leg takes place next Sunday, 8 May at Ashton Gate at 15:15 BST while Doncaster's return match will kick off at Castle Park at 14:30 BST.
Tries from Will Hurrell, Andrew Bulumakau and a penalty try have given the Knights a 13-point lead to take into the second leg with Carnegie's retiring fly-half Kevin Sinfield scoring one of their three tries.
Bristol, beaten in the two-leg final by just a point at Worcester a year ago, finished the regular Championship season last weekend with a 39-6 win at Bedford.
They scored four first-half tries through Ollie Robinson, James Phillips, Ross McMillan and Jack Wallace with Philips adding another after the break and Jack Tovey got a sixth try.
Hooker Charlie Clare got Bedford's only try while stand-off Jake Sharp kicked three penalties as well as a conversion.
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