Marcos Ayerza says he is looking forward to the big stage of a Wembley World Cup clash with defending champions New Zealand.Argentina get their Rugby World Cup campaign underway today against the All Blacks, the defending champions, at the home of football (kick-off 4.45pm).   Leicester Tigers prop Ayerza starts in the front row for Los Pumas and says it will be a fantastic occasion.   “They are the world champions,” said Ayerza. “They are the No1 team in the rankings. They are the All Blacks.   “We have played them over the last four years many times and we know how good they are.   “I am very much looking forward to the big occasion, oplaying at Wembley, the first game of the World Cup. It will be fantastic.   “In the last year we have won against Australia, South Africa and France away. Those games bring us the confidence that on our day we can be very competitive and beat any team in the world.   “The All Blacks are the All Blacks, we have prepared ourselves as well as we can and we will give it a go.”   Leonardo Ghiraldini, Ayerza’s front-row colleague at Welford Road, captained Italy in their opening game of the World Cup on Saturday but could not prevent the Azzurri from going down to a 32-10 defeat at Twickenham.   Hooker Ghiraldini played just over an hour of the clash, while his Tigers teammate Michele Rizzo came on from the bench for the final 30 minutes.   Freddie Michalak kicked France into a 15-3 half-time lead before Rabah Slimani touched down in the second half. Giovanbattista Venditti hit back with a try for Italy but Nicolas Mas scored his first try in 81 Tests to secure France’s win.