Atletico Madrid moved two points clear of Barca at the top of the table, having played a game more, thanks to substitute Thomas Partey's late winner to edge past Levante 1-0 yesterday.
Real Madrid now trail Atletico by five points ahead of their trip to Valencia on Sunday.
Lionel Messi and Luis Suarez hit the woodwork for Barcelona either side of half-time, but Espanyol's physical approach was rewarded with a first point against Barca in eight matches.
Espanyol committed 22 fouls despite a lenient approach from referee Jose Luis Gonzalez, but Luis Enrique refused to blame the officials for a stuttering start to the new year.
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"Football is a contact sport," he added.
"That is why we have a referee there to control the game."
The first of three meetings between the sides in 10 days got off to a frenetic start with Espanyol forcing Barca onto the back foot.
Their best chance came from a set-piece, though, when Alvaro Gonzalez's header was brilliantly stopped by Claudio Bravo and Gerard Pique hooked the ball to safety off the line.
Messi then struck the angle of post and bar with an almost perfect free-kick as Barca began to take control just before the break.
The hosts had another slice of luck when Suarez could
only strike the outside of the post after rounding Pau Lopez and turning away from Gonzalez moments later.
Messi should have done better when he fired straight at Lopez when well placed on the edge of the area and the Espanyol 'keeper made another comfortable save from Neymar's acrobatic effort as they restricted Barca to surprisingly few clear openings in the final stages.
At the Vicente Calderon, Atletico's struggle for goals continued, but they were bailed out by an error from Levante 'keeper Diego Marino 10 minutes from time.
"Once again the changes gave us the quality we needed in the game, especially in the movement for the goal," said Atletico boss Diego Simeone.
Marino undid his good work earlier in the game as he got down brilliantly to turn Jackson Martinez's low drive to safety.
Simeone's men's luck appeared to be out when Koke unleashed a piledriver from Martinez's knockdown against the bar.
However, their persistence was rewarded when just as against Rayo Vallecano in midweek, Partey came off the bench to make the telling contribution as he skipped through the heart of the Levante defence but his shot ought to have been stopped by Marino as it trickled into the net.