City's Bernardo Silva and Mateo Kovacic both misfired in the shootout to put Madrid in the driving seat
Ronaldo scored twice in three minutes to salvage a point for Real and deny Las Palmas a first ever win at the Bernabeu, converting a penalty and heading home from a corner one minute from time.
A Jonathan Viera penalty put the visitors ahead in the 56th minute after Bale had been dismissed for two bookings and Kevin Prince-Boateng stretched Las Palmas' lead, but Real, who had three goals ruled out, refused to give in.