The Blues top the table by two points, but found it tough going against a spirited and resilient Coleraine side.
Linfield had the most of the chances, with Phillip Lowry unlucky not to find the net when he saw his goal-bound effort beaten away by Eugene Ferry.
However the Bannsiders had chances of their own, with Howard Beverland almost finding the net in the second half only for his effort to be headed onto the crossbar by Aaron Burns.
Tommy Breslin's side meanwhile were guilty of squandering a host of chances in their game at the Oval, but in addition to their own wastefulness they also found themselves up against Elliot Morris in defiant mood.
In addition to a series of misses by the visitors the Glens stopper pulled off a string of fine saves over the course of the game, but the Reds will wonder how they didn't come away with the three points.
Curtis Allen had the best opportunity for Glentoran but his first-half effort struck the post.
With both of the teams above them failing to win, third-placed Portadown closed the gap at the top of the table with a 3-0 win over Warrenpoint Town.
Chris Ramsey opened the scoring for the Ports after just eight minutes when he headed home from a Darren Murray cross, and following a brilliant penalty save from David Miskelly Gary Twigg added a second with an easy finish from Josh Barton's low cut-back in the 18th minute.
It was Twigg who completed the scoring when he steered the ball past Jonathan Parr after a great through ball from Sean Mackle as Ronnie McFall's side earned a deserved win.
In the game at Seaview Crusaders made short work of bottom side Ards, despite going a goal down early on.
William Faulkner set up Ross Arthurs to score in the first minute, but Eamon McAllister's fine 12th minute volley drew the sides level before Jordan Owen's 25th minute shot proved too hot to handle for Ards stopper Alan Blayney after he had kept out Gary McCutcheon's initial effort.
With the Stephen Baxter's side now firmly in control McCutcheon got his name on the score sheet with a composed finish in the 58th minute, before Joshua Robinson diverted a McAllister shot into the net in the 76th minute to complete the scoring.
The result keeps the Crues just a point behind Portadown in the table, with the Belfast side also having a game in hand.
Elsewhere on Saturday Ballymena United picked up their first win in three games with victory over Glenavon at the Ballymena Showgrounds.
The Sky Blues opened the scoring when James McGrath could only clear Jonny Taylor's goal-bound effort into the path of Darren Boyce, whose shot was in turn deflected into the net by Mark Patton.
Patton equalised for the visitors with a fabulous curling strike in the 63rd minute, but Boyce had the final say, connecting with an Allan Teggart cross at full stretch to turn the ball in and seal a 2-1 victory.
Finally Dungannon Swifts and Ballinamallard United played out a 1-1 draw at Stangmore Park.
Ryan Campbell capitalised on some static Dungannon defending to open the scoring in the 19th minute, racing on to a long clearance upfield before lifting the ball over Swifts keeper Gareth Buchanan.
However the Mallards' lead only lasted until a minute before half time, with Matt Hazley scoring steering in Gary Liggett's cross from close range to secure a share of the spoils.
Saturday's results in full:
Ballymena Utd 2-1 Glenavon
Ballymena Utd: Boyce 36, 68.
Glenavon: Patton 63.
Coleraine 0-0 Linfield
Crusaders 4-1 Ards
Crusaders: McAllister 12, Owens 24, McCutcheon 58, Robinson 76.
Ards: Arthurs 1.
Dungannon Swifts 1-1 Ballinamallard
Dungannon Swifts: Hazley 44.
Ballinamallard: Campbell 19.
Glentoran 0-0 Cliftonville
Portadown 3-0 Warrenpoint Town
Portadown: Ramsey 8, Twigg 18, 30.