Casey Stoner\'s victory in last weekend\'s Spanish MotoGP at Jerez means there is now just one circuit remaining on the present 18-round calendar that the Australian has not won at in the premier-class. And that circuit is Estoril, venue for this weekend\'s Portuguese Grand Prix. Stoner took a 250cc victory at the track in 2005, with his best MotoGP finish a second place in 2009. The events forming the MotoGP calendar have been unchanged since 2010. Stoner, Repsol Honda\'s reigning double world champion, starts this weekend just four points behind Yamaha\'s Jorge Lorenzo in the standings. Lorenzo has a stunning Estoril record, claiming three wins and one second place during his four MotoGP appearances - and has qualified on pole each time. Meanwhile, the official MotoGP stats show that Stoner\'s 41st grand prix victory moves him into the all-time top ten, with just one win less than Max Biaggi and Toni Mang.