Paulao scored with his head into the lower left of the goal after intercepting a pass from Real Sociedad's Antoine Griezmann.
Defender Paulao produced an excellent all-round outing for Los Beticos. He scored one goal, blocked two shots and made eight clearances.
Rubén Castro scored on a header for Real Betis in the 81st minute.
Los Verdiblancos suffered a setback when Mario was given a red card in the 88th minute. Despite the loss in man power, Real Betis coped well for the remainder of the match and pulled off an impressive win. Beticos attempted 10 shots, including four on target.
Real Sociedad controlled possession for about half the contest thanks to strong open field play. Real Sociedad won 66 duels and 21 headers, which led to seven shots, including five on target. The six attempts by Carlos Vela were the most of any Real Sociedad player. The combination of Daniel Estrada to Xabi Prieto was the most common during the match, as the two players connected 14 times. Diego Ifrán was brought on to replace David Zurutuza in the 70th minute when the latter went down with an injury.
Even though Real Sociedad ended up controlling the possession overall, it was Real Betis that had the ball for most of the first half, with 54.4% possession. Real Sociedad trailed at the break despite outshooting Real Betis, 9-6.
Verdiblancos now sit in fourth in the table with a record of four wins, three losses and zero draws. Real Sociedad are in 12th place with a record of three wins, four losses and zero draws.