Lionel Messi handed his side the lead in the 15th minute when he fired home a penalty after Alexis Sanchez was fouled. An own goal from Jordi Figueras helped them double their advantage, but Ruben Castro netted for the visitors.
Messi got his second of the game after tapping in the rebound from his missed penalty to secure the victory.
Sports Mole analyses the game to see if Gerardo Martino's men deserved their win.
On target: 4
On target: 4
Was the result fair?
Barcelona had the better of the first half, but were never truly at the free-flowing best in the final third of the pitch. Messi showed his predatory instincts from the penalty spot and from his follow-up from his missed kick in the second, while the home side benefited from some luck as Jordi turned the ball into his own net. Betis had their moments especially in the second half where they dominated for large periods. They didn't show a clinical edge in front of goal, which is the reason they came away from the Camp Nou with nothing, but they may have deserved a point for their effort.
Martino's side were far from their best. Their communication in the final third of the pitch was poor and there far too many occasions when players were not on the same page. They could have been more clinical in front of goal as well as Messi, Cesc Fabregas and Alexis Sanchez all spurned opportunities. Defensively they were cut open at times when Alfred N'Diaye, Alvaro Vadillo and Leo Baptistao all had chances, which on another day could have come back to haunt them. Barcelona needed the three points and Martino will be pleased to see that they did battled enough to earn them to close the gap on Atletico.
Betis held their own for the majority of the game and will be disappointed to come away with nothing. They had their moments in front of goal and Vadillo, Cedrick Mabwati and N'Diaye will all feel that they could have done better and that was the difference between the sides. The home side did just enough to eek out the win while not at their best, while the visitors spurned their chances and made a couple of mistakes at the back. It's those fine margins in which games are decided and Betis failed to come through in the critical moments.
Sports Mole's man of the match
Lionel Messi: Even though the 26-year-old wasn't at his best during the game, he still did enough to ensure that his side got the three points. He could have had more than the two goals he netted as he came close with two shots that went just wide of the target. His first penalty was well struck but his second was poor, although he had the alertness to capitalise on the rebound fire his side to the win. Not at his most potent but still the match-winner.
It wasn't the best game for Jordi at the back for Betis. It was his foul on Sanchez that handed Barcelona their first penalty and in the second half he guided the ball past his own keeper from Pedro's pass to double the home side's lead. Two big errors that cost Betis a point.
Eduardo Prieto had a steady game. He was correct in awarding the first penalty when Sanchez was brought down. The second was a tad harsh on Juanfran as the ball hit his hand when it was at his side, the decision could have gone either way but he gave the spot kick. He seemed to get every other decision spot on and a good outing at the Camp Nou.
Barcelona: Martino's side face Atletico Madrid in the second leg of the Champions League quarter-final on Wednesday.
Real Betis: Betis hosts Sevilla in La Liga next week.