Teenage star Alexis Thompson shot a second round 66 to take a two-shot lead at the halfway point of the Dubai Ladies Masters, the season-ending championship on the European Tour.The 16-year-old Thompson, who became the youngest ever winner on the LPGA Tour when she triumphed at the Navistar LPGA Classic in Alabama, had six birdies at the Majlis course of Emirates Golf Club.The American leads Sweden\'s Sophie Gustafson (67) and Margherita Rigon (68) of Italy who are on six-under par.Julieta Granada of Paraguay and Wales\' Becky Morgan are a shot further back with Michelle Wie, the highest ranked player in the field at 17, in a four-way tie for sixth on four-under after carding a 67.Lotta Wahlin of Sweden, the overnight leader, is among the quartet on 140 after a second round 74.The 500,000 euro tournament features the cream of European Ladies golf with Japan\'s Ai Miyazato having already secured the Order of Merit crown.