Published: 2020-02-10 04:15:09 BdST
French defender Clement Lenglet headed home the decisive goal in the 72nd minute from a Messi freekick but was then sent off for two bookings, moments after Betis' Nabil Fekir had been dismissed for earning two yellow cards in one instance.
Barca had fallen behind in the sixth minute to a penalty from Sergio Canales after a VAR review showed Lenglet had handled the ball, but Dutch midfielder Frenkie de Jong promptly equalised with the help of a lofted pass from Messi.
Betis restored their lead with a strike from World Cup-winning forward Fekir in the 26th minute but Barca struck back again right before halftime when Messi found Sergio Busquets with a freekick and the midfielder converted from close range.
The win allowed second-placed Barca to cut the deficit behind league leaders Real Madrid back to three points with 23 games played after Real beat Osasuna 4-1 earlier in the day.