The home team went ahead in the first half through a header from Kris Boyd, but Brian Kerr brought Motherwell level soon after the interval.
Rangers were denied a penalty when substitute Filip Sebo appeared to be brought down by Mark Reynolds.
However, the visitors could also point to their own penalty claim when Scott McDonald was upended by Brahim Hemdani in the closing minutes.
Nacho Novo was first to threaten for the home team with a fine run and shot which went narrowly wide.
Barry Ferguson's powerful volley was blocked by Jamie Paterson before Charlie Adam's 30-yard free-kick was held by keeper Colin Meldrum.
Novo showed great skill along the byline before winning a corner from which Rangers took the lead.
Thomas Buffel played a shot corner to Ferguson before crossing to the back post where the unmarked Boyd headed powerfully home from close range.
After the break Richie Foran's header went close before Motherwell equalised.
McDonald advanced into the box and his cross was only half cleared to Kerr at the edge of the box and he drilled his shot home with the aid of a deflection.
Rangers responded to the setback and Novo's powerful shot from Boyd's flick was well saved by Meldrum.
After Sebo's strong penalty claim was waived away, Motherwell were denied a penalty when McDonald was tackled from behind by Hemdani.
There was still time for Meldrum to produce a marvellous save from Buffel in the last minute.