Leaders Hearts dropped Scottish Premiership points for the third game running as they played out a goalless draw with Motherwell.
The visitors had goalkeeper Alexander Schwolow to thanks for some superb saves as Motherwell created the better chances.
The Tynecastle side move five points clear but Celtic, who have two games in hand, can move within two should they beat Hibernian on Sunday.
Motherwell and Hearts sides produced one of the games of the season when they last met back in August as Derek McInnes' side rallied from 3-0 down to snatch a draw at Tynecastle.
Hopes were high for a similarly free-flowing game, but chances were few and far between in the first half.
Stuart Findlay was robbed of possession in his own penalty area by Elijah Just, who squared for Tawanda Maswanhise, but the in-form Zimbabwe international could not make a clean connection and the chance was lost.
Motherwell had the ball in the net when Elliot Watt clipped a cross into the box and Callum Hendry stretched to convert. The celebrations among the home fans were shortlived, though, as the VAR ruled the goal out for offside.
Just passed up a glorious opportunity early in the second half when he headed straight at Schwolow having been picked out beautifully by Maswanhise.
After being largely outplayed in the first half, Hearts came out with greater purpose and quicker tempo after the break.
They thought they had taken the lead when Lawrence Shankland met a corner to send a looping header goalwards, only for Callum Hendry to intervene with a brilliant goalline clearance.
Moments later Maswanhise had a goal ruled out for offside before Schwolow produced three big saves in as many minutes to deny substitute Ibrahim Said, Lukas Fadingar and a free-kick from Callum Slattery.

Motherwell played the better football, created the better chances, but lacked the killer instinct to claim the win their play deserved.
Some of their football was scintillating, though in the first half the moves were largely breaking down in the final third.
What they were at all times was brave on the ball, willing to take on the risky pass to start on attack.
There was also variety to their play. The patient build-up is good, but they are not afraid to clip a ball over the top for Maswanhise to get in behind and stretch the defence.
The chances started to come in the closing stages, and only the excellence of Schwolow in the Hearts goal stopped Motherwell finding that breakthrough.
McInnes before the match had played down any notion there might be a dent to the confidence of his Hearts players after they lost their unbeaten league record last weekend at Aberdeen.
The first-half display at Fir Park suggested otherwise, with the league leaders looking off the pace as Motherwell pressed them into making mistakes and, at points, played around them at will.
Hearts did defend pretty well, and played with more purpose and tempo early in the second half, but were second best for long spells.
As has been proved more than once this season, Fir Park is a tough place to go these days and a point is by no means a bad return, especially given the balance of play.
However, it is now only one win from five for Hearts. And while only one of those was a defeat, if Hearts are to stick around at the summit, they will need to start turning draws into wins again pretty soon.
Motherwell travel to face Falkirk in the Premiership on Wednesday (19:45 GMT), while Hearts welcome Kilmarnock to Tynecastle at the same time.