Barcelona continued their imperious form this season as they retained top spot in Champions League Group G with a 2-0 victory away to Benfica
u00a0
Alexis Sanchez struck after six minutes and Cesc Fabregas added a second following the break to leave Barca with a 100 per cent record from their opening two games.u00a0
u00a0
Sergio Busquets was sent off with two minutes to go after a clash with Maxi Pereira.
u00a0
Now Tito Vilanova's men turn their attention to the small matter of the El Clasico on Sunday against Real Madrid - but they will be without Carles Puyol, who dislocated an elbow after falling heavily on his arm.u00a0
u00a0
Puyol is expected to miss around eight weeks of action.
