Josep Guardiola’s men made an explosive start at Camp Nou as Xavi Hernández opened the scoring after ten minutes and Lionel Messi took his league tally to 18 shortly afterwards. The game was far from won, though, with Rubén Castro reducing the deficit just after the half-hour and Roque Santa Cruz levelling after the break, but a second yellow card for defender Mario left Betis with ten men for the final 20 minutes.
They were made to suffer soon after as Alexis Sánchez rifled in from the edge of the area five minutes later. Messi then wrapped up the win with a penalty four minutes from time following a handball by José Antonio Dorado Ramirez.
Earlier in the day, Athletic climbed to fifth, four points behind Levante, courtesy of a commanding 3-0 success against the Valencia-based outfit.
That was also the scoreline as Atlético Madrid beat second-bottom Villarreal as Falcao scored twice, while Óscar Trejo’s added-time effort sealed a 2-1 victory for Real Sporting de Gijón against Málaga that lifted his side to 18th.