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 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 No. 1, 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. Points, bidding for his second title after the 2011 Pebble Beach Pro-Am and a second start at the upcoming Masters, started on the back nine and birdied his first five holes out of the gate before another on the 17th for a scorching 30 at the turn. Adding further birdies at three, seven and eight, Points rolled in over 160 feet of putts through the round with a new putter, but said he had been struggling mentally in the leadup. A number of players are battling to crack the world's top 50 after the tournament's conclusion and earn a last-minute invitation to the Masters. Augusta native Charles Howell III and Swede Henrik Stenson shot 69 to be tied 18th, while 2006 US Open champion Geoff Ogilvy, Australia's last major winner, was level with McIlroy at one-over. Prayad holds on to lead In Bangkok, Thailand's Prayad Marksaeng maintained his title charge at the inaugural $750,000 Chiangmai Golf Classic with a five-under-par 67 in the second round Friday, stretching to a two-shot lead. The six-time Asian Tour winner is on a 12-under-par 132 total, but a host of big names are hot on his heels, including Thailand's Thongchai Jaidee and Asia's first Major champion Y.E. Yang of South Korea. Thongchai shot an impressive 65 to move to tied second place with American Jonathan Moore (68) and India's Digvijay Singh, who birdied his last three holes for a 67. China's Hu Mu stayed in the title hunt with a solid 69 for tied fifth place, while Yang shot 68 to tie in 12th. Four-time Major winner Ernie Els of South Africa struggled to a 71 for tied 41st place on 140. — Agencies