Rangers lost the initiative in the SPL title race after they were held to a draw by Motherwell at Fir Park.
Christian Dailly took advantage of a poor decision from goalkeeper Graeme Smith to head Rangers in front.
But Chris Porter stabbed home from close range to level matters early in the second half.
The beaten Uefa Cup finalists are now three points behind leaders Celtic with a game in hand. Their goal difference is also inferior to Celtic's by seven.
Rangers travel to St Mirren on Monday before ending the campaign at Pittodrie on Thursday, when Celtic visit Dundee United.
Following two defeats and two draws on their league travels, Rangers knew they could not afford another slip-up.
Walter Smith's side started strongly but could only find one goal before the interval and Motherwell responded with a strong second-half showing.
With Mark McGhee's team struggling to retain possession, the visitors were lively in the opening stages.
They were given several opportunities to exploit Motherwell's weakness at set-pieces only to be let down by a series of poor deliveries.
Nacho Novo was given a sight of goal on 20 minutes as excellent passes from David Weir then Barry Ferguson opened up the home team, but the striker's shot from the edge of the penalty box was deflected wide.
Soon after, Smith did well to hold a thumping drive from Daniel Cousin.
However, the goalkeeper was to blame for the opening goal, which arrived after 29 minutes.
Kirk Broadfoot shelled a long free-kick into the penalty box and Dailly rose to beat the flapping Smith and nod into an unguarded net from 15 yards.
Motherwell posed little attacking threat until right-back Brian McLean strode forward on 41 minutes to unleash an angled shot that Neil Alexander did well to tip away.
Just seconds into the second half, Cousin muscled his way past two opponents, but Smith got down well to save as the striker charged in on him.
And, within a few minutes, Motherwell were level thanks to Porter's 18th goal of the season.
With the target at his mercy, David Clarkson sent a header against the post.
But McLean was first to the loose ball and his low pass was flicked on by Steven McGarry and Porter added the finishing touch from inside the six yard box.
Rangers replied with a fierce shot from Cousin, while Charlie Adam curled a free-kick inches wide and then tested Smith with a powerful strike.
The visitors laboured in the closing stages and the home side looked the more likely side to snatch a winner on the break.
Motherwell: Graeme Smith, Brian McLean, Craigan, Reynolds, Hammell, Darren Smith (Fitzpatrick 66), Lasley, Hughes, McGarry, Porter, Clarkson (Murphy 74). Subs Not Used: Daniels, Lappin, McCormack, Connolly, Meechan.
Booked: Craigan, Lasley.
Goal: Porter 50.
Rangers: Alexander, Broadfoot, Cuellar, Weir, Whittaker, Adam (Darcheville 77), Dailly, Ferguson, McCulloch (Davis 66), Cousin, Novo (Boyd 82). Subs Not Used: Graeme Smith, Furman, McMillan, Fleck.
Goal: Dailly 29.
Att: 10,445
Ref: J Underhill
BBC Sport Player Rater man of the match: Rangers' Nacho Novo 6.86 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.
