Low and Gordon Reid will start in the front row while Calum Forrester makes a welcome return to action from injury. Michael Doneghan earns a start on the wing with Steven Manning being rested.
Robbie Fergusson retains the stand-off berth and kicking duties following his match-winning conversion last week while Josh Dunning begins in the second row.
“Last week’s victory away to Plymouth Albion was well-earned,” said an Ayr spokesman. “Coming back from 17-5 down at half-time to win 17-18 showed great determination and character and there has been a real buzz in training this week.
“Cross Keys will prove another tough challenge but the players will want to put on a good performance in front of the home support. Our opposition played in their first B&I Cup tie last Saturday and won comfortably agaisnt Moseley by 47-3 so we anticipate a difficult game.
Ayr 15 – Grant Anderson 14 – Michael Doneghan 13 – Richard Dalgleish 12 – Mark Stewart (captain) 11 – Cameron Taylor 10 – Robbie Fergusson 9 – Murray McConnell; 1 – Gordon Reid 2 – Hayden Wisnewski 3 – Moray Low 4 – Josh Dunning 5 – Robert McAlpine 6 – Andrew Dunlop 7 – Calum Forrester 8 – John Willis
Replacements: 16 – Stuart Fenwick 17 – Andrew Kelly 18 – Alan Brown 19 – Richard Hawkins 20 – Johnnie Beattie/ Colin White 21 – AJ McFarlane 22 – Sylvain Diez
Cross Keys: 15-Gareth David 14-Kristian Baller 13-Leon Andrews 12-Phil Williams 11-Nathan Trowbridge 10-Steffan Jones 9-Rhys Dyer 1-Richard Cornock 2-Gerwyn Price 3-Craig Gould 4-Dan Hodge 5-Tom Lampard 6-Rhys Peebles 7-Rob Nash (capt) 8-Jevon Groves
Replacements: 16-Lewis Rawlins 17-Jamie Sollis 18-Marc Jones 19-Marc Popham 20-Luke Williams 21-Nathan Williams 22-Owen Jones.