There's nothing happen except lucky, Las Palmas is just lucky they can beat Barcelona in Barcelona's home. Barcelona have dominated the ball possession, shots more than Las Palmas, no red card, they've all out. Even though Barcelona didn't play with their best eleven, but the substitute players have decent qualities.
It is not wrong to say that Las Palmas won with luck, because looking at the match statistics, we can actually judge who deserves to win. But the problem is that in football dominating and creating many opportunities is not enough, because what determines whether they win or not is the number of goals they can score. Luck also cannot be obtained just like that, because Las Palmas also tried well, especially in maintaining defense and taking advantage of the opportunities they got. Although they didn't get many opportunities, once they got the opportunity they could convert it into a goal.