By David Anderson & Dan Marsh Robert Lewandowski settled Barcelona’s nerves to keep alive Xavi’s hopes of bowing out as manager with a trophy. Lewandowski netted Barcelona’s crucial third goal seven minutes from time in the Olympic Stadium – after Napoli’s Jesper Lindstrom missed a great chance to level the tie. Barcelona started on fire and scored two goals inside two first-half minutes with former Leeds winger Raphinha instrumental. First, the Brazilian cut Napoli open down the left and pulled the ball back for Fermin Lopez to slot home in the 15th minute. Then he curled a right-foot shot ag…