Constant rainfall left the pitch bogged down with water, not allowing either side to truly play with the ball on the floor.
The game, which was hit by torrential rain, did not see its first goal until the 66th minute when Gerard Moreno converted Sergio Garcia's cross with a thumping header.
Granero won the ball in midfield before finding Garcia in space down the right, and after Lucas Digne failed to close him down, the veteran winger swung in the ideal cross beyond Pique for Moreno to stoop and head beneath Ter Stegen.
"There's a very long way to go, we have to continue on the same path", Correa told Movistar.
After that match, Pique's tone when talking about Espanyol infuriated rival fans and prompted an official complaint by the club.
"Celebrating the goal was special after everything that's happened in the last week", Pique said post-game.
With Barcelona struggling to create in the first half, the Argentine was eventually brought on after 58 minutes and his presence changed the game.
As has so often been the case down the years, Messi was able to rescue a point for Barcelona despite not starting the match, and fans took to Twitter to share their thoughts on him.
Tensions were high from kick-off after the controversy surrounding the veteran's comments about Espanyol following the recent Copa del Rey tie. And while things are not as bad as first feared, he's expected to be out for up to two weeks.
The former Liverpool man completed 83% of his passing, failing to link up with his new team-mates. The hosts were good value for their point and negated Barcelona's high-flying attack, keeping Coutinho and Luis Suarez at arm's length throughout the contest.
Espanyol will feel they deserved a win, although a draw against this Barcelona side - even in conditions which level the playing field and perhaps even give you an advantage - is a creditable result.
"Ernesto Valverde's team move past the record set by Pep Guardiola's team in 2009/10 who started the season unbeaten in their first 21 matches before losing 2-1 to Atlético Madrid in week 22", the website added. Espanyol will be roared on by their own fans, but they know that the visitors are the favourites to win this game.