HOUSTON – American D.A. Points shot a sparkling eight-under 64 to take a one-shot lead after the opening round of the Houston Open on Thursday, while Rory McIlroy continued his underwhelming start to the year at Redstone Golf Club.The 36-year-old Points, who had struggled with seven missed cuts from nine events for the season, shrugged off the dismal form with nine birdies and a solitary bogey to be one stroke clear of countrymen Cameron Tringale and John Rollins.A week after being unseated by Tiger Woods as world number one, Northern Ireland’s McIlroy battled to a one-over 73 after a poor front nine saw him reach the turn at three-over.McIlroy found some form with four birdies coming in, but added another two bogeys to be well off the pace in his last warm-up before Augusta."I felt like on the front nine I was a little tentative and I made a couple of silly mistakes, making double on the par-five there so I just went down and tried to commit to my shots more on the back nine and it seemed to help,” McIlroy told reporters.Augusta native Charles Howell III and Swede Henrik Stenson shot 69 to be tied 18th, while 2006 U.S. Open champion Geoff Ogilvy, Australia’s last major winner, was level with McIlroy at one-over.