Matt Bettencourt and Peter Tomasulo opened the Valero Texas Open, both with -5 under par 67, to lead by just one shot at TPC San Antonio, in Texas. Peter Tomasulo and Matt Bettencourt / Getty Images Matt Bettencourt overcame the severe asthma problems that had been dogging him, thanks to some new medication. Matt said he was never worried about his game, just his health; " My game hasn't been the concern, I've gone back and forth from three to four different inhalers and some different medications, which has helped my health, but I haven't been able to play golf with it at all." Peter Tomasulo was happy to get round with no bogies, for his -5 under par round; ' I just played a solid round of golf to go around here with no bogies. We got a good end of the draw, I think, with the weather calming down late in the day." Padraig Harrington and Billy Horschel are tied in third place, along with Bryce Molder and Harris English, all of them at -4 under par. Padraig just coming back from a snowy Ireland said it was not as cold over the Atlantic; " Last week back in Ireland, it was snowing, and I didn't feel as cold." Billy Horschel said he had another good day on the golf course, after challenging last week; "All in all, it's a good day, I could hit the ball a little bit better, but I did a good job of managing it and making a couple putts." World number two, Rory McIlroy, entered the tournament as a final opportunity to gain some form in time for next week's Masters at Augusta National, he opened with an even-par 72 and is tied for 45th. Rory said his mistakes are more mental than physical; " More mental than anything else, It's just about limiting those mistakes. It's definitely more mental mistakes than physical." There are ten players, including Jim Furyk and Brian Davis, who are only two shots back of the leaders, they are at -3 under par for the tournament.