Barcelona didn't have an easy job at all though. It was like they were waiting for Valencia to score to start performing better. 
Lewandowski was on his very good day that he scored two goals. It is good to see him being beneficial for his team. Because he is one of top earners in the squad now. Therefore the expectations are bigger as well.
I still believe it could be his last year at Barcelona on one hand. He is 35 and has 2 years left on his contract. If he plays much extra this season then maybe the team could consider keeping him for one last year.
Actually, it was as I thought that Valencia would make it quite difficult for Barcelona. Especially if we see the home team leading first, it certainly made the Barcelona players a little panicked to be able to reply to the goal. But Hansi Flick did show his experience in managing a big team and the result was this narrow victory that allowed Barcelona to steal 3 points from Valencia's home. Lewandowski was on his very good day that he scored two goals. It is good to see him being beneficial for his team. Because he is one of top earners in the squad now. Therefore the expectations are bigger as well.I still believe it could be his last year at Barcelona on one hand. He is 35 and has 2 years left on his contract. If he plays much extra this season then maybe the team could consider keeping him for one last year.
Despite Lewandowski's good game, he certainly realized that he would not be able to last much longer at Barcelona and the management must have reminded him of the striker regeneration in the future. So while he is at Barcelona, he will continue to contribute with his goals and regarding his departure later, Barcelona may not let him go for free and therefore if there is a profitable moment, Barcelona will also be happy to let him go.