Kevin Stadler came to the HSBC Champions tournament with few expectations. He was even prepared to have a bad week in China. What mattered was being free of the pressure of the U.S. tour, where he has struggled to find his niche. Instead, Stadler led two-time Masters champion Phil Mickelson by one shot, carding a 3-under 69 on Friday for an 11-under 133 total to top a field that includes 10 of the…