The Yorkshire derby saw tries from Tara Moxon and Eboni Partington put York in control at half time but Izzy Northrop and Jenna Greening went over, and Mel Howard’s sole conversion edged Rhinos ahead.
Zoe Hornby scored against her old team to restore the Valkyrie lead but Frankie Blakey and another Howard conversion made it 16-14 to the away side.
York stepped on the gas after that, as Emma Kershaw and Moxon’s second try earned them a 24-16 victory.
Challenge Cup finalists St Helens racked up their first Super League win of the season with a comfortable 36-0 win at Huddersfield Giants which takes them third in the table.
After initial strong resistance from a Giants side which won at Warrington Wolves last week, Vicky Whitfield sparked Saints into life by scoring with her first touch after going on as a replacement.
Dani McGifford added another try before half time and after the break further scores from Georgia Sutherland, Chantelle Crowl, Phoebe Hook, Rachael Woosey and Darcy Stott eased them to victory as Luci McColm added four conversions.
