Ivan Rakitic opened the scoring, Messi caught up with Real Madrid's Cristiano Ronaldo on 35 trebles in all competitions and Arda Turan completed the rout, with Turkey's captain scoring his first goal for the club since joining from Atletico Madrid.
Barca's victory, which saw them beat the undefeated record Real Madrid had held since the 1988/89 season, restored an eight-point lead at the top over Atletico with 11 matches to go.
Atletico beat visiting Real Sociedad 3-0 on Tuesday, while third-placed Real Madrid are again 12 points off the pace after a 3-1 win at Levante on Wednesday.
Barca were helped by the fact that Rayo lost defender Diego Llorente to a red card three minutes before halftime for a foul on Rakitic before Manuel Iturra was also sent off in the 67th for bringing down Sergio Busquets in the area.
Busquets was felled from behind going for the rebound after a Messi free kick came back off the bar but Luis Suarez's penalty was saved by Juan Carlos, Barcelona's ninth miss from 18 penalties in all competitions this season.
Liverpool owners admit to underrating gravity of rebuild
The former general counsel for Liverpool owners Fenway Sports Group (FSG), Edward Weiss, revealed they had 'underestimated' how poor the squad actually was and were 'overconfident' about rebuilding the club they purchased in 2010.
The admissions came during a Supreme Court hearing in New York this week relating to a long-running legal dispute with Mill Financial, an American company, suing the club's former co-owner George Gillett Jr and the Royal Bank of Scotland.
"You know, I think we underestimated how poor the playing quality of the (Liverpool) squad was, and frankly, we underestimated how difficult it was going to be to stabilise the asset," Weiss said.
"We were overconfident in assuming that many of the things that we had done in Boston at Fenway (with the baseball franchise Boston Red Sox) would translate naturally to the Premier League, and they just didn't all translate."
At the time of the take over, the Liverpool squad included club icons Steven Gerrard and Jamie Carragher but Weiss suggested they inherited a team with a few players past the peak of their careers.
"What we came to know was that the playing squad was poor. While we had a few top players like Steven Gerrard, other players like Fernando Torres and Pepe Reina were probably beyond their prime," Weiss said.
Since FSG took over the club, Liverpool won the League Cup in 2012 but only finished in the top four of the Premier League once, when they came second in 2014. (Reporting by Shravanth Vijayakumar in Bengaluru; Editing by John O'Brien)
source: www.abs-cbnnews.com
