With just 11 points from 19 matches, Espanyol still face an uphill battle to avoid relegation, but they can take satisfaction from frustrating their city rivals' bid to take sole possession of first place, reports Efe news.
Instead, Barca find themselves tied on points with Real Madrid at 40, though the Blaugrana have the edge on goal difference.
Espanyol started brightly late on Saturday, as the players were anxious to make a good impression on new coach Abelardo Fernandez and give the team's long-suffering supporters at RCDE stadium something to cheer about.
Even so, Barcelona dominated possession and the hosts' first shot of the night came only in the 23rd minute, but it proved to be worth the wait, as David Lopez got his head to a Marc Roca free kick for the 1-0.
The star-studded visiting squad failed to respond and Espanyol delighted their fans with long spells of possession until the final five minutes of the half, when Barcelona stirred to life.
Espanyol keeper Diego Lopez coped easily with a Lionel Messi header in the 41st minute before Luis Suarez hit the post on the ensuing sequence.
Right before the break, Messi missed the mark on a free kick.
Barca coach Ernesto Valverde made a change to start the second half, replacing Ivan Rakitic with Arturo Vidal, and the move paid off five minutes later when Jordi Alba's cross found Suarez unmarked and the Uruguayan levelled the score at 1-1.
Vidal put Barcelona ahead in the 59th minute with an assist from Suarez.
Espanyol were paying the price of their exertions in the first half, prompting Abelardo to use all three of his substitutions in the span of 12 minutes in a desperate bid for a draw.
In the 75th minute, the hosts caught a break in the form of a second yellow card for Barcelona's Frenkie de Jong, sent off for the first time in his career.
The home side pressed hard to exploit the man advantage, yet the impact was negligible and it looked like Barca would see out the match until Wu Lei got the equaliser for Espanyol in the 88th minute.
Matias Vargas assisted on the goal by the Chinese striker, who came on in the 74th minute.
( With inputs from IANS )