With the two powerhouses set to meet in nine days in a "clasico" that could well decide the title race, Ronaldo kept Madrid four points ahead of its rival after matching his own record of 40 league goals in one season Wednesday by scoring a hat trick in a 4-1 win over Atletico Madrid.
That made the Portugal forward the first player from Europe's major leagues to record two consecutive 40-goal seasons.
"Records are there to be broken but that's not my aim, my aim is to bring Madrid the title," said Ronaldo, who can improve his scoring mark Saturday against Sporting Gijon.
Ronaldo's hat trick — which included two spectacular long-range strikes — put him one goal ahead of Messi in the league scoring race and took his overall season tally to 52
Messi, however, has 61 goals overall which leaves the Barcelona forward only two shy of matching Everton's Dixie Dean's 63-goal tally from the 1927-28 season.
With Messi's own penchant for hat tricks, it wouldn't be a surprise if he matches or surpasses Dean's tally Saturday when Barcelona is at Levante.
Beyond Dean, Messi could also challenge Ferenc Deak's total of 66 goals scored for Hungary's Ferencvaros during the 1948-49 season, Brazil great Pele's 66-goal tally for Santos in 1958 and Gerd Mueller's 67 from 1972-73.
Messi has scored 24 times in his last 13 appearances to help Barcelona win 10 straight league games and narrow the gap to Madrid from 10 points to four ahead of their April 20 clash at the Camp Nou.
Barcelona midfielder Ibrahim Afellay was cleared to play Saturday, while defenders Daniel Alves and Gerard Pique remain doubtful for the trip to the Ciutat Valencia stadium, where Madrid lost earlier this season.
"The pressure is on," Barcelona midfielder Sergio Busquets said. "We're doing our job, which is to win. That's in our hands, anything else we have no control over."
Sporting upset Madrid at the Santiago Bernabeu last year to hand coach Jose Mourinho his first home loss in league play in nine years. While the Asturian club is coming off a 3-2 victory against Levante that lifted it off last place, Madrid's attack has been a juggernaut and is three goals away from matching the league record 107 it scored during the 1989-90 season.
"We want to reach the end of the season with the league and Champions League won, that's the objective," said Ronaldo.
Madrid plays Bayern Munich in the Champions Leagu semifinals while Barcelona faces Chelsea, and the two Spanis clubs are tipped by many to square off again in the final in Munich on May 19.
In other 33rd-round games, it's: Espanyol vs. Valencia; Zaragoza vs. Granada; Real Betis vs. Osasuna; Malaga vs. Real Sociedad; Villarreal vs. Racing Santander; Athletic Bilbao vs. Mallorca; Rayo Vallecano vs. Atletico; and Getafe vs. Sevilla.