SIMON Dyson endured a difficult third round in the Shell Houston Open as he carded a six-over par round of 78 at Redstone Golf Club.

The York ace, who posted rounds of 73 and 71 on the opening two days, started on the back nine on Saturday.

After a birdie on the tenth, he dropped four shots in four holes before salvaging a shot on the par-five 15th.

The front nine followed a similar pattern, with Dyson bagging a birdie on the second hole before dropping five shots over the next five holes.

With several players still out on the course, Dyson had dropped 26 places down the leaderboard to a tie for 72nd place.