Cameron Percy is one shot further back after his round of 70, Brett Drewitt and Cameron Smith both signed for even par 72, former winner Steven Bowditch 73 a score he shared with John Senden and professional debutante Curtis Luck while Greg Chalmers was round in 75.
South African, Grace, finished this event off strongly last year to record a top ten finish, that coming a week after his breakthrough PGA Tour victory at the RBC Heritage. The multiple European Tour winner recorded seven birdies and a bogey, continuing his solid recent form which included an 11th place finish at Hilton head last week.
Grace leads by one over John Huh, Stewart Cink and Will MacKenzie.
Luck recovered from a horror start to his professional career, bouncing back from bogeys on his opening three holes to be at even par turning for home. He then dropped shots at his 10th and 12th holes before holing a bunker shot for eagle at his 14th hole, the short par four 5th of the TPC San Antonio layout.
With the cut appearing as if it will fall around the even par or perhaps 1 under mark then Luck will need an under par effort tomorrow if he is to cash his first ever prizemoney cheque.