Just 14 of the 76-strong field broke par on one of the toughest days of the year but none of them were Irish as Seamus Power shot 74 and Graeme McDowell a 76 in the Valero Texas Open.
Both men are now tied for 50th on two-over par, ten strokes behind Kevin Chappell (71), who leads by one shot on eight-under par from Branden Grace (70) and John Huh (71) after a windy third round in Texas.
With an average score yesterday of 74.34 (+2.34), TPC San Antonio easily ranked the toughest course of the year on the PGA Tour so far.
It ranked ahead of Augusta National's average for the week of 73.877 during this year's Masters (+1.887), 72.89 at Bay Hill's (+0.890) for the Arnold Palmer Invitational and 72.766 (+0.766) at Torrey Pines (South) for the Farmers Insurance Open.
With an average score so far this week of 73.056 (+1.056), TPC San Antonio is second only to Augusta National's 73.877 (+1.877) at this year's Masters for difficulty.
McDowell went out in 35 but came home in 41, three-putting twice as he got little reward from hitting 12 of 14 fairways.
Power moved up 14 places despite mixing three birdies with five bogeys in his 74.
Playing in his rookie season, the West Waterford man ranks highly in several statistical categories — Strokes gained (SG) Around-the-Green (18th), SG Putting (31st), Driving distance (27th with 300.8 yards), Sand Saves (T23rd, 60.00%), Clubhead speed (24th 119.52mph), Approaches from 50-75 yards (13th) and Approaches from 150-175 yards (11th).