Charley Hoffman has a one-shot lead at the Shell Houston Open following a first-round 64, while world number two Jordan Spieth is three shots behind.
Spieth is warming up for the defence of the green jacket as there are just six days before the start of The Masters at Augusta.
The 22-year-old had just one blemish on his opening round as he suffered a bogey on the 10th hole, but his six birdies were enough to keep him in contention for the title on five-under-par.
Hoffman carded an eight-under round following one bogey and nine birdies, four of which he hit consecutively from the first hole, while Dustin Johnson sits just one shot behind his fellow American following a first-round 65.
Rickie Fowler is five shots off the pace after carding a three-under-par 69 round, while three-time Masters champion Phil Mickelson is in the same position in the field.
