The Argentina captain then linked up with pal Luis Suarez for a liquid second.
Getafe defended well to take a 0-0 draw at Valencia, keeping its hold on fourth place.
Betis more than matched the league leaders for much of the first half and could have taken the lead after just 13 minutes when Joaquin's diagonal ball was turned back into the area by Cristian Tello, but Jese Rodriguez could not get the required contact on it in the middle when a better finish would have left Marc-Andre ter Stegen little chance.
Suarez limped off injured in the final minutes and Messi could have added a fifth, only for the post to rescue Betis. Messi said he had never received such a tribute from opposing fans. Tello's cross went behind Jese but came to the substitute Diego Lainez. "Whenever we come to this stadium they treat us very well, very grateful and happy for the victory, which was very important".
The pound climbs 1.7% this week as no-deal Brexit voted down
The motion to extend the UK's exit was put forward to MPs at Westminster yesterday (Thursday) and was passed by 413 votes to 202. Mr Rutte said the current Withdrawal Agreement is the "only deal on the table".
Lionel Messi netted the first goal in the 18th minute from a superb free-kick to give Barcelona the lead.
There are 10 rounds remaining, but with Messi and his teammates playing at this level and with such a large cushion of points, only a complete collapse could deny Barcelona a 26th league title and its eighth in 11 years. Vidal threaded through a wonderful through ball for Messi, who squared the ball for Suarez but the Uruguayan striker could only shoot tamely on his left foot straight at Lopez.
'It's significant that they cheer him, it's an acknowledgement'.
In the second half he rounded the keeper but his cross-shot was off target, before being sent through again but firing wide. "But we didn't suffer at all", said Messi, who will return to Argentina duty in the upcoming global break, via Sport.
In this matchup I'm not giving a lot of chances to Betis because their defense is shaky and offensively, they can't produce enough to top Messi, Suarez and Coutinho so I'm going to side with Barcelona.