Lionel Messi opened the scoring from the penalty spot after 15 minutes and Jordi Figueras, who had conceded the spot-kick, doubled Barca's lead with an own goal midway through the second half.
Betis striker Ruben Castro quickly pulled one back for the visitors but Messi struck again in the 85th minute, reacting quickly to having a penalty saved to send the ball in on the rebound and seal the three points.
"In a sense I was expecting today's match to not play out like our previous ones. For once, I'm going to focus 100% on the result, not how we played," said Tata Martino, who added: "I don't want to make excuses. The feeling that I have is that in between the game this past Tuesday and the one next Wednesday this match against Betis snuck up on us. We needed to win in order to continue putting pressure on the leaders."
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