A fantastic game of football saw the Argentine sensation break two goalscoring records as the Blaugrana did just enough to escape from Seville with three points.
The Argentine etched his name in football history with his 85th and 86th goals for club and country in 2012, breaking the 40-year-old record of 85 set by Gerd Muller in 1972, while he also surpassed Cesar Rodriguez as the all-time league goalscorer for the Blaugrana with his 192nd Liga goal.
Messi's brace put Barcelona two goals up after 25 minutes, but it was far from smooth sailing for the Catalans, who were given a thorough examination by a spirited home side that pulled a goal back through Ruben Castro shortly before the break.
The attacking pressure from Betis saw the team create a number of opportunities in the second half, hitting the woodwork twice, but Barca managed to ride its luck and grind out the victory, which gives the team its 14th win in 15 league games, and restores a six-point lead over Atletico Madrid at the top of the table.
Messi shook off a knee injury sustained during the 0-0 draw against Benfica midweek to start in a much-changed side from Tito Villanova, who retained only two players from his XI against the Portuguese outfit.
Betis fired an early warning shot with just over two minutes on the clock, after a good moment in possession from Joel Campbell saw him pick out Salva Sevilla inside the area, but his header was placed too close to Victor Valdes.
Barca was handed a blow after 10 minutes, as Cesc Fabregas, who appeared to be struggling, was withdrawn, with Alexis Sanchez coming on in his stead.
But the visiting side did not break stride, and with just over a quarter of an hour gone, a driving run from Messi saw him past multiple defenders on his way into the area, where he finished calmly into the bottom corner to equal Muller’s record.
Betis nearly conceded again within moments of the restart, but were thankful to goalkeeper Adrian for holding his nerve to tip a clever lob from Andres Iniesta over the crossbar.
The resistance would not last long though, and when a one-two saw Iniesta tee up Messi inside the area with a delightful back heel, the Argentine’s finish for his 86th goal in 2012, and his place in the footballing pantheon, was inevitable.
Adrian was called into action again to deny Xavi from 20 yards out, but just when it seemed like Barca was set to run away with the game, Betis managed to pull a goal back shortly before halftime.
The Blaugrana’s defense was nowhere as organized as the attack, as Jordi Alba failed to read the offside trap set by the rest of the back line, allowing Castro in behind to slot comfortably past Valdes.
Pepe Mel’s team was the superior side to start the second half, and behind an ever-raucous crowd, controlled possession and created chances as it pressed forward at the Barca goal.
Valdes nearly gifted Betis an equalizer shortly after the interval after spilling a harmless cross from Sevilla, before recovering just in time to claw the ball around the post ahead of the onrushing Castro.
With 20 minutes remaining, a wayward defensive header from Javier Mascherano off a Betis corner saw the ball rebound off the inside of the post and into the grateful arms of Valdes.
Matters were whipped into a frenzy with a flurry of chances during the closing stages. First, Pedro was slipped into space by Sanchez, but he could not direct his finish home as Adrian was able to block.
Pozuelo then crashed a 20-yard half-volley off the woodwork, a let off which was soon matched by Barca as Messi blasted a shot on the turn onto the post, before Alba directed the rebound onto the crossbar from point blank range.
Thiago blasted a shot into orbit from eight yards out as somehow the scoreline remained intact. The final whistle signaled three points to the Catalans, bringing an end to an enthralling game of football.