Play was delayed more than five hours because of the wind. The two leaders had played just one hole in the morning before play was suspended.
Lowry three-putted the par-5 to finish at 1-under 71, leaving him at 16-under 200 entering the final round. Rock made a 20-foot putt for birdie for a 69.
Lowry is trying to become the second amateur to win on the European tour this year following Danny Lee in the Johnnie Walker Classic in Perth, Australia, three months ago. Rock has been second twice this year and is going for his first victory in his seventh year on tour.
Johan Edfors of Sweden had a 68 for the days best round and was two strokes behind. Graeme McDowell of Northern Ireland, who shot a course-record 61 in the second round, withdrew Saturday because of shin splints.
Lowry took a two-stroke lead into the third round after his 62 in gentle conditions Friday. He stayed in front until the last hole. His third shot put him within 30 feet. He putted six feet past the cup and missed.
I felt a bit nervy playing the last, but I still feel I can win, he said.
Rock hit a poor second shot at the 18th. He followed with a 9-iron that left him 20 feet away, but he holed the putt.
It was still very windy, Rock said. You had to stay focused on every shot.