It cannot always be a laugh a minute. Paris Saint-Germain will play Arsenal in the Champions League final and they made sure of that by getting serious, nullifying an off-key Bayern Munich and rarely wobbling after adding to their first-leg lead. Luis Enrique’s team should have won by more in a match that did not, and probably never could, hit the previous week’s heights but their triumph was underpinned by an aptitude for the dirtier work that would serve them