The 21 year old Englishman only turned professional when he came through The European Tour Qualifying School in November but a one under par outward 34 took him to six under par in Mallorca.
Nixon, who finished 11th in Andalucía in March, had four birdies and would have overtaken overnight leader Grégory Bourdy but for a double bogey at the third and a dropped shot at the eighth.
France's Bourdy was seven under after breaking the course record with an opening 63, and was amongst the afternoon starters on day two.
Nixon had pulled level with compatriot Danny Willett - another player with a late tee time - while Ireland's Simon Thornton was making a significant charge up the leaderboard.
Thornton lost his card last season but at five under with two to play he was up to three under and a share of sixth.