Barcelona: Barcelona continued their record start with 17 wins and a draw to maintain their 16-point lead over third-place Madrid. The leaders opened up a 12-point advantage over second-place Atletico Madrid ahead of their game later at Mallorca.
Barcelona coach Tito Vilanova returned to the touchline for the first time since undergoing throat surgery to remove a second tumor in two years on December 20. Barcelona dominated Espanyol from the start at Camp Nou stadium and made quick work of the relegation-threatened side after Xavi Hernandez scored in the 10th from a pass by Iniesta.
Pedro Rodriguez then added two more goals, first volleying in a cross from Cesc Fabregas in the 15th before chipping in Sergio Busquets' perfectly weighted pass in the 27th. Two minutes later, Messi scored from a spot kick after Fabregas had been fouled by goalkeeper Kiko Casillas in the area. The loss was Espanyol's first in five games under new coach Javier Aguirre.
Last season, Messi set a league record with 50 goals. He already has 27 before the season's midway point. Atletico striker Radamel Falcao is next with 17th, followed by Ronaldo's 16.
Messi converted a penalty in Barcelona's 4-0 thrashing of crosstown rival Espanyol, while Ronaldo scored twice in a three-minute span to give 10-man Real Madrid a hard-fought 4-3 victory over Real Sociedad.
Messi, who finished 2012 with a record 91 goals, is the favorite to win the Ballon d'Or for an unprecedented fourth time. Ronaldo collected the award in 2008. Messi's teammate, Iniesta, has never won football's highest individual honor.