Antoine Griezmann scored twice on his Camp Nou debut for Barcelona, turning around a match which saw the Catalans come from behind to thrash Real Betis 5-2.With Lionel Messi and Luis Suarez both missing for the hosts, the pressure was on the Frenchman to deliver and he played the part of main man, scoring either side of half time to inspire Barca to their first win of the season after defeat to Athletic Club last week.Nabil Fekir gave Real Betis the lead after 15 minutes, angling a tremendous low finish into the far corner of the net as the visitors cut open Barcelona on the break. But Griezmann met a Sergi Roberto cross on the stretch to restore parity before half time.Griezmann curled a left-footed finish home after 50 minutes with youngster Carles Perez adding a third for Barca soon after. Jordi Alba and substitute Arturo Vidal netted a fourth and a fifth before Loren Moron lashed home a stunner, but it was little more than a consolation goal for Real Betis