The Gers returned from their UEFA Cup Final defeat to Zenit St Petersburg knowing that a win was a must if they wanted to keep their title hopes in their own hands.
But the draw now means that Celtic are favourites to secure the league title in the final round of games on Thursday.
The match got off to a high-tempo start although neither side really tested the two goalkeepers. It took until midway through the first half before the visitors took a firm grip on the game.
Home keeper Graeme Smith had saved well from Nacho Novo and Daniel Cousin before he committed a dreadful error to hand Rangers the lead in the 29th minute.
He came rushing off his goal-line in an attempt to punch a long Kirk Broadfoot clearance away but Christian Dailly was first to the ball and his header bounced into the unguarded net.
Just before the break, the home side created their first real opportunity when Neil Alexander had to tip over Brian McLean's 12-yard shot.
Rangers should have doubled their lead within a minute of the re-start when Cousin burst onto a long ball and left Mark Reynolds and Stephen Craigan in his wake. However, when he drove into the box he was denied by a fine one-on-one save by home keeper Graeme Smith.
Rangers were punished for that miss within five minutes when Motherwell grabbed an equaliser.
Stephen Hughes' cross was headed on to the post by David Clarkson, and when Darren Smith returned the ball into the box, Chris Porter was on hand to poke the ball home at the front post.
Despite a late onslaught from Rangers, the home side held on for a point which puts a huge dent in the Glasgow side's title hopes.