Alexis Sanchez and David Villa made the most of a rare place in the starting line-up with goals either side of Messi's strike and Andres Iniesta, Cristian Tello and Gerard Pique were also on the scoresheet as a rampant Barca racked up a 20th victory in 23 matches to move on to 62 points.
Atletico were upset 2-1 at Rayo Vallecano in Sunday's late kick-off and stay on 50 points, four ahead of third-placed Real Madrid, who thrashed Sevilla 4-1 at the Bernabeu on Saturday thanks to a Cristiano Ronaldo treble.
"We are not going to repeat all the praise we have showered on him [Messi]," Barca sporting director Andoni Zubizarreta said in an interview with Spanish TV broadcaster Canal Plus.
"Alexis and Villa gave us a lot of speed and created spaces and showed they are also capable of putting the ball away," the former Barca and Spain goalkeeper added.
"Some of the players who don't feature so often were very impressive."
Barca's interim coach Jordi Roura, standing in for Tito Vilanova who is recovering from throat surgery, rested several key players for Getafe's visit to the Nou Camp, including Spain trio Pedro, Cesc Fabregas and Sergio Busquets.
They were also missing playmaker Xavi through injury, with Thiago Alcantara and Iniesta running the show in midfield in the absence of their Spain team mate.
Unusually, Barca had been handed the midday kickoff slot but the unfamiliar starting time failed to dampen the players' hunger for victory in front of more than 85,000 fans thronging the giant arena and enjoying the sunshine.
Alexis struck in the sixth minute, Messi made it 2-0 seven minutes later and Villa put the game well beyond Getafe, who are 12th on 29 points, with a third just before the hour.
As Getafe started to wilt, Messi surged forward and laid the ball off for substitute Tello to curl in a fourth 11 minutes from time before a mistake from Jordi Alba let in Alvaro Vazquez to pull a goal back for the visitors in the 83rd minute.
Iniesta, who caused Getafe constant problems with his pace and guile, fired in from close range in the 90th and Pique rounded off the party in the second minute of added time with a tap-in from Thiago's unselfish layoff.
"There is nothing to say about the match, we just have to forget it and think about the next game," Getafe coach Luis Garcia told a news conference.
"You cannot do much more because you just don't get the ball," he added.
"You can't get the ball off them and when you do it's after a huge effort and you are a long way from goal."
Atletico slipped to a second defeat in three games at city rivals Rayo, with a goal from Radamel Falcao in the fifth minute of added time serving only to make the scoreline slightly more respectable for Diego Simeone's men.
Lass fired Rayo ahead in the third minute and Leo Baptistao doubled the home side's lead just after the half-hour.
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